Sutton's Bedsente Gomis has a shot on goal against Leeds
Leeds United saw Premier League promotion rivals Newcastle and Brighton crash out of the FA Cup yesterday.
And the Elland Road club showed little interest themselves in progressing to the fifth round and ended the game with 10 men.
Sutton deservedly won the game through Jamie Collins, who side-footed home from the penalty spot on 52 minutes.
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But they should have been ahead way before then as Leeds goalkeeper Marco Silvestri saved his side time and again.
Leeds manager Garry Monk made 10 changes to the side that beat Nottingham Forest 2-0 in midweek.
And the West Yorkshire side, currently fourth in the Championship, struggled to retain the ball in Sutton’s half for much of the game – such was the intensity the hosts brought to the game.
Sutton United sold out their ground for the FA Cup clash
Garry Monk made 10 changes to his Leeds United side
Roarie Deacon had Sutton fans cheering just minutes into the game when he found the net – only for the offside flag to save Leeds’ blushes.
Silvestri then produced flying saves to again deny Deacon and Bedsente Gomis.
Monk responded to Leeds’ woeful display by throwing on £3million summer signing Kemar Roofe with 18 minutes remaining.
But they failed to record even a shot on target as defender Liam Cooper was sent off with nine minutes remaining for a second bookable offence.