Edwin van der Sar concedes Sunday's defeat at Arsenal has allowed Chelsea back into the title race, with the Dutchman well aware Manchester United missed a glorious opportunity to tighten their grip at the Premiership summit.
The 36-year-old goalkeeper was twice beaten late on at Emirates Stadium by first Robin van Persie, seven minutes from time, and then again courtesy of Thierry Henry's last-gasp header.
After taking the lead early in the second half through Wayne Rooney, United had looked all set to open a nine-point gap over Chelsea, who a day earlier had endured an Anfield aberration in going down 2-0 to Liverpool.
Van der Sar believes United must now regroup, put the late capitulation behind them and focus on the next job in hand, which is to negotiate a three-point haul from their next league game, against Watford at Old Trafford.
"We have kept Chelsea in it," he conceded to the club's official website.
"It could have been a good weekend for us and it would have been nice to take advantage of their (Chelsea's) mistakes at Anfield.
"If we could have made the gap nine points or seven points, then it is further away than six and good for us. I just hope it doesn't give Chelsea a lift.
"It was poor for us to lose the game like that. We were on our way to a clean sheet and playing with confidence. We are bemused by what happened.
"Nevertheless, we are still ahead and better off than we were last year. We must now concentrate on winning our next league game against Watford."