Jason Walker's pinpoint finish gave York City the points at the R Costings Abbey Stadium as Cambridge United failed to make the most of playing against ten men for more than 45 minutes.
City's Ben Gibson was dimissed just before half-time for a high tackle on Jonathon Thorpe, but United struggled to make the most of their advantage, and Walker's goal gave the Minstermen the win their performance deserved.
Jez George made one change to the U's side, with Liam Hughes coming in for the injured Kevin Roberts. Hughes took up a position on the right side of midfield, with Thorpe dropping in to right-back.
York had 42-year-old player/coach Paul Musselwhite making his debut in goal after an injury to regular stopper Michael Ingham, but United failed to test the veteran despite a bright showing in the opening 45 minutes.
Hughes was inches away from a spectacular goal when he volleyed Michael Gash's cross just wide from the edge of the box, while Gash and Luke Berry both had on target efforts easily saved by Musselwhite.
At the other end former Histon man Lanre Oyebanjo got clear on goal but poked a shot wide, before the dismissal of Gibson changed the complexion of the game.
After a determined run forward he appeared to lose control of the ball and flew in on Thorpe. Referee Bull had no hesistation in giving the midfielder his marching orders, despite the protests of the visiting players.
Even then York should have gone into half-time in front, but Chris Smith's header from an Oyebanjo free kick was superbly saved by Naisbitt.
Thorpe was unable to continue, meaning Jack Eades came on to fill an unfamiliar role at right-back for the second period. United struggled to get going, with York passing up several good chances before Walker struck the decisive blow.
Following a U's corner, the Minstermen broke down their right, with Matty Blair finding Walker, who advanced into the box before drilling a shot across Naisbitt and into the far corner.
In the closing stages the home side pushed forward, but were unable to create a chance of note, and slipped to their first defeat in six matches.
Man of the Match: Danny Naisbitt - Couldn't stop the winner, but had made a couple of outstanding saves to keep York at bay.
FULL TIME: Cambridge United 0-1 York City
21.35: That's full-time, a poor second half from the depleted U's has seen the ten-men of York City come away with a win that looked unlikely when Ben Gibson was dimissed just before half-time.
21.33: Hughes goes for the spectacular and clears the cross-bar with ease. York make a final change, Walker trudges across the entire width of the pitch, milking the applause of the travelling fans. His superb goal looks likely to give the visitors the points. Matty Blinkhorn is on for the last minute.
21.32: Three minutes to be added rather than the regulation four, I suspect the extra 60 seconds wouldn't be crucial in any case.
21.31: We're into the 90th minute, and York are holding the ball down in the corner until the lino gives the U's a sympathy free kick. Good cross comes in from Eades as United go forward but Hughes can't connect.
21.27: Difficult to see United getting anything out of this match, but you never know. Jez punts a new ball onto the pitch in frustration as the previous one disappears over the Habbin. I guess the boss will be annoyed his team have failed to make the most of their extra man, but on the other hand with the players we have - or don't have - available, it was always going to be difficult to deal with the visiting front line, which is decent to say the least.
21.24: Better from United, passing the ball forward before Jarvis works it wide to Eades, whose cross is blocked behind. Corner comes in from Jarvis, Hughes tries a back-heel at the near post but that's not troubling anyone and trickles out for a goal kick.
21.22: Change for United, James Brighton on in place of Shaw, who has been treading water for some time. Brighton will play wide-left, Hughes up front, Pell back into his native midfield.
21.17: The U's aren't exactly making the most of their extra man, but have a corner here as Parslow heads behind. Poor from Jennings, but it's behind again and JJ will try again. Again York clear and United are wide open as Chambers sprints free. Eades tries to hold him off but the striker back-heels into the path of Blair, who dribbles a shot wide.
21.13: United have gone three at the back since the goal, with Eades and Hughes wide and Pell up front with Gash. But York continue to impress, and Blair gets to the byline and wins the Minstermen a corner. It's inswinging and claimed by Naisbitt.
21.12: Enterprising play from Jennings and United win the corner. Outswinger from JJ but that's easy for Musselwhite.
21.11: There can be little doubt York deserve their lead on the balance of chances. United haven't really extended Musselwhite all game, and won't do so here as Eades cross is overcooked and flies out at the far post.
21.08: United with a corner now as Shaw's shot deflects away. There's a scramble at the near post and ball goes wide of the head of McAuley I think.
21.06: GOAL CAMBRIDGE UNITED 0-1 YORK CITY. United have a corner but York break away and find Jason Walker just inside the United half. The striker carries the ball down the right channel into the box before drilling a brilliant low finish across Naisbitt and into the far corner. Poor defending from United to allow him to get the shot off but a brilliant finish from the ex-Barrow man none-the-less.
21.03: Yellow card. Meredith late on Pell, that'll be a yellow card. Meredith is aghast but he can have few complaints.
21.01: Oyebanjo hobbling off for York, very slowly of course. Another injury for York. Potts is his replacement.
21.00: Chambers roasts Hudson down the York right and bursts into the box, but McAuley gets a foot to his cross and deflects it away from a couple of waiting attackers.
20.58: York with a corner, won by Walker off the shins of McAuley. It's a poor one though, and Naisbitt claims the cross easily. United need to calm this down, patience will be required and at the moment they're trying to force things too much. Jez George's side could do with a few minutes when they keep the ball and try and stretch York.
20.55: Today's attendance is 2,211, 226 away fans.
20.53: Corner comes in and Smith gets free again but mistimes his header and it's wide. York look up for this, United look nervous.
20.51: Yellow card. Shaw stretches to halt another run from Meredith, and fouls the York man. Fairly sure that wouldn't have been a booking pre-red card, but of course it is now. Free kick comes in, half away, Oyebanjo picks up the ball and charges down the York. The cross is missed by a defender and Walker shoots into the ground but Naisbitt pulls off a good save to tip the ball over the bar, the Minstermen top scorer should've buried that.
20.49: Big test for Eades and Hughes this half, a winger and a striker playing right-back and right-midfield respectively. Just as well United have an extra man.
20.48: Meredith eased off the ball and York have a free kick 35 yards. In it comes, flicks off Berry, and Hughes hooks out for a throw in down in the corner. Challinor's delivery is long but Hughes heads clear.
20.46: The teams are back and United have been forced into a change, Jonathon Thorpe obviously hasn't recovered from the Gibson red card incident, so Jack Eades is on his place at right back. Not sure whether Eades has ever played right-back before, but we'll find out soon enough I'm sure.
HALF TIME: Cambridge United 0-0 York
20.32: That's half-time, fairly entertaining stuff, York have had the better chances, through Oyebanjo and Smith, but they will have to play the entire second half a man down and it will be up to United to make their advantage count. Stay tuned.
20.29: Yellow card. Of course the York players are trying their luck now, United make a hash of a clearance in the left corner and ball breaks to Chambers, who goes for an Ashley Young-esque tumble over Jennings' outstretched leg. Barely even a free kick, but the U's skipper is in the book and York have a chance to deliver into the box. In it comes from Challinor, Smith climbs highest but Naisbitt makes a tremendous one handed save to parry the ball away, top goalkeeping. United clear the danger, that was a let-off.
20.24: RED CARD. Now this makes things interesting. Ben Gibson makes good progress into the United half, but over-runs the ball on the edge of the box and flies into Thorpe The referee has no hesitation in brandishing the red card. Looked a bit high but it was on the far side of the pitch to me so I wouldn't like to comment too much. Anyway, United with the man advantage.
20.21: Walker and Chambers combine again, with Chambers trying to curl a shot over Naisbitt and putting it well over the bar.
20.16: Long ball over the top finds Gash in space on the left. He controls well and tries to play in Shaw. A defender blocks and the rebound falls kindly for Gash, who goes for goal himself but Musselwhite makes a comfortable save.
20.13: United break with Shaw, who gets the ball wide to Hughes, but his cross is too near Musselwhite, who claims ahead of Berry and Gash, United win the ball back from the restart though, Pell escapes down the left and pulls the ball back to Jarvis. He works it on to Berry whose shot on the turn is smothered by the keeper.
20.10: Not a bad game this, both sides trying to play though York probably look the more accomplished. Here comes Jarvis for United though, flighting a cross towards Gash, it's headed away as far as Hughes who causes a defender to put the ball behind. United corner, Jarvis's first cross is low, it's cleared out to Jennings, who finds Jarvis again, and though Gash gets a flick on the cross this time York clear.
20.06: Blair arrows a cross into the near post straight into Naisbitt's body, but the keeper fumbles it behind. Another cheap corner, but Walker is climbing all over the back of a defender and the U's have a free kick.
20.04: Early change for York, with Chris Doig exiting with some kind of injury. Danny Parslow takes his place. 20.00: Berry and Pell not quite on the same wave-length there as Berry's step-over is intercepted. But again York's clearance is poor and Pell seizes on a loose pass and wellies a 25-yarder wide of the goal.
19.58: York are starting to crank up the pressure, Chambers getting free in the left channel, cutting back in-field and chipping a shot into Naisbitt's hands.
19.55: Walker's through ball bisects the United defence, and Oyebanjo nips in ahead of his former Histon team-mate Naisbitt but can only steer a shot just wide. That was the closest the visitors have come so far.
19.50: United profit from a poor clearance, the ball from Smith intercepted and worked to Gash, who chips his cross to the back of the box where Hughes tries to guide a volley into the net but sees it flash inches wide. That would have been a spectacular goal. 19.49: Hughes with the cross and Berry flicks a header straight at Musselwhite. That had neither the power nor direction to trouble the keeper.
19.48: Jennings tries to dribble his way out of trouble in the corner under pressure from Chambers, but lets the ball run out for a corner. Bit of a cheap one that, but the initial delivery from Oyebanjo is blocked and Naisbitt grabs his second cross.
19.46: Challinor is at right-back for York, where he has been for most of the season, but Meredith, usually a left-back, is in centre-midfield with Oyebanjo. Whatever works I suppose. Thorpe makes good progress down the right but his cross is easily snatched by Musselwhite.
19.43: Musselwhite is 42 apparently, this is his York debut. Both teams far from full-strength. York are about to get us off and running, attacking the NRE. A good smattering of Yorkies in the South Stand give their team a pre-match roar of encouragement.
19.41: Here come the teams, York in blue and white with the U's, as usual, donning amber and black. Referee this evening is Mike Bull. The sun's going in and it's getting cold, brr.
19.33: Another note on the York side is that regular keeper Michael Ingham is missing, with player/coach Paul Musselwhite between the sticks. Not sure exactly how old Musselwhite is, but think he was around when I started watching football some 20 years ago. Goalkeepers eh.
Cambridge United: Naisbitt, Thorpe, Jennings, McAuley, Hudson, Hughes, Pell, Jarvis, Shaw, Berry, Gash. Subs: Corker, Eades, Brighton, Hurst, Ambrusics.
York City: Musselwhite, Oyebanjo, Meredith, Smith, Doig, Challinor, McLaughlin, Blair, Chambers, Gibson, Walker. Subs: Parslow, Reed, Potts, Tonne, Blinkhorn.
19.26: TEAM NEWS. United make one change, with Liam Hughes coming into the line-up at the expense of the injured Kevin Roberts. It remains to be seen whether Hughes, who scored in this fixture last season, will play wide or up top alongside Michael Gash. I suspect the former. Jonathon Thorpe will drop back into his usual right back position to cover Roberts. York include ex-U's James Meredith and Jon Challinor in their starting line-up, along with former Histon full-back Lanre Oyebanjo. The dangerous Jason Walker, who scored a late equaliser at Bootham Crescent earlier this season when the side's drew 2-2, is in the side.
19.23: Hello everyone and welcome to the R Costings Abbey Stadium for tonight's match, Cambridge United against York City. While United are pretty much playing for pride with just three matches of the season left, the visitors need the points to bolster their play-off aspirations.
Reporting by Matt Gooding.