Sir Alex Ferguson admitted Manchester United had only themselves to blame for failing to kill off Chelsea before Salomon Kalou rescued a 1-1 draw in Sunday's Premier League showdown. South Korea winger Park Ji-Sung put United ahead in the 18th minute at Stamford Bridge but Ferguson's side couldn't get the crucial second goal.
Kalou punished them as he came off the bench to level with 10 minutes to go, leaving United lagging six points behind Chelsea and seven adrift of leaders Arsenal.
"We started the game well and I thought we dominated it," Ferguson said. "If anything we should have been going for the jugular when it was 1-0. "I feel we have missed a good chance obviously. If we had had a bit more energy we would have been OK.
"We started to drop off the pace a bit in terms of the speed we were playing at. That was a bit of a disappointment because it allowed them to regroup at half-time. "Didier Drogba is a big physical force and they could knock long balls to him and change the type of game it is.
"We started to give the ball away in the second half and that got them back into the game. They had a couple of chances, but that's about all they had."
Ferguson was frustrated that referee Mike Riley booked six United players in a fussy display that often broke up the play for both teams. "People on television are saying they can't believe what was going on," Ferguson added. "It's hard to know what you can say about referees."
Although United have won just one of their first four league matches, Ferguson believes they will make up ground once Cristiano Ronaldo and Dimitar Berbatov are fully fit.