Coventry City were defeated 1-0 by Leyton Orient at the Ricoh Arena despite having the better of the chances at the Ricoh Arena.
Josh Wright scored 13 minutes from time to hand Orient the three points in the crucial game in the League One relegation fight.
The game didn't start in the best vein for the Sky Blues, as in form striker Dominic Samuel limped off with what looked like a knee injury after just ten minutes, which provoked Tony Mowbray into bringing on young Academy striker George Thomas.
Orient had a great chance before the half hour mark, when Mathieu Baudry powerfully headed a corner inches wide of the post from eight-yards.
The Sky Blues then went extremely close themselves to the opener shortly afterwards, when Frank Nouble beat his man on the left and his cross was met by Jim O'Brien, but the skipper's looped effort flew inches away from the right-post from six-yards.
Former City loanee Chris Dagnall then had the best opening of the half right on the stroke of half-time, as he ran in behind the City rearguard and met a deflected ball into the box, but his header was well saved from Lee Burge with what looked a certain goal from six-yards.
That was the last action of the first-half but City started the second brightly. Grant Ward smashed the upright with a wonderful curling drive just a minute after the restart from inside the area after he cut inside from a short corner.
City then had three chances in five minutes as they built massive momentum, first it was Thomas who had an effort cleared off the line as he latched onto Alex Cisak's parry and had an open goal on the right side of the box, but Baudry did well to get onto the line and nick it away.
Ward then went close again as his swerving effort from 20-yards was tipped over by Cisak. From the resulting corner, Aaron Martin completed the trio of great chances as he headed the ball at the front post inches over.
But after that dominance, Orient took the lead against the run of play with 13 minutes remaining, when Dagnall took down a long ball and fed Wright at the back-post who slotted the ball comfortably past Burge at the near post.
The visitors were then able to see the game out as they emerged victorious in the crucial relegation battle in League One.
Coventry City: Burge, Willis, Pennington, Martin, Stokes, Ward, Fleck, O'Brien (C) (Haynes 81), Odelusi (Turgott 81), Samuel (G.Thomas 10), Nouble.
Subs: Charles-Cook, Phillips, C.Thomas, Barton.
Leyton Orient: Cisak, Cuthbert, Baudry, McAnuff (James 64), Lowry, Clarke (C), Wright, Bartley, Dagnall (Omozusi 84), Henderson, Taylor (Hedges 59).
Subs: Omozusi, Simpson, Plasmati, Woods.
Attendance: 8010 (596 away)
Referee: D Bond
Yellow cards: Nouble