Leeds' faltering Coca-Cola League One promotion push suffered another setback as they went down 2-1 to Walsall at Elland Road.
Julian Gray set up Dwayne Mattis to put Walsall ahead a minute after half-time but Gary McSheffrey's deflected cross sailed in to level the scores eight minutes later.
The Saddlers were not to be denied, though, and Clayton McDonald's header nine minutes from time was adjudged to have crossed the line despite Casper Ankergren's best efforts, leaving Leeds with only one win in seven league games after their first home league defeat since January 2009.
Colchester took full advantage, beating Yeovil 1-0 at Huish Park to move third, three points behind Simon Grayson's men.
Kayode Odejayi scored the only goal from just outside the penalty area in the 38th minute after being teed up by Clive Platt.
Huddersfield won 2-1 at Carlisle in the night's other League One game. Lee Novak scored Town's first from close range in the sixth minute and Jordan Rhodes headed in Gary Roberts' corner to double their lead (56) before Joe Anyinsah's last-minute consolation.
Copyright (c) PA Sport 2009, All Rights Reserved.