A controversial equaliser from Gareth Ainsworth gave struggling Wycombe Wanderers a 1-1 draw at promotion-chasing Colchester United.
Ainsworth headed in Matt Phillips' cross from close range amid protestations for handball, to cancel out Ian Henderson's opener.
Wycombe went close early on when Ainsworth's looping header from Kevin Betsy's free-kick sailed inches wide.
Colchester rarely threatened Chairboys goalkeeper Tom Heaton in the opening 45 minutes, though David Prutton scooped a shot wide and Steven Gillespie headed over from six yards.
Williams palmed over Stuart Beavon's 25-yard thunderbolt and Adam Hinshelwood headed inches wide for Wycombe. But Colchester broke the deadlock just before the hour-mark when Henderson chested down Kem Izzet's pass and lashed a fine shot into the far corner.
Dean Keates and Jon-Paul Pittman went close before Ainsworth headed home in the third minute of stoppage time.