Manchester United defender Wes Brown insists he was fouled by Didier Drogba and Chelsea's winning goal at Stamford Bridge should not have stood.
Chelsea scored the only goal of a tight encounter on 76 minutes when John Terry's header from Frank Lampard's free-kick took a nick off Nicolas Anelka and crept inside the far post.
United were unhappy with the goal, feeling the free-kick awarded for Darren Fletcher's challenge on Ashley Cole was harsh and that Drogba committed a foul after Terry headed the ball on.
Drogba appeared to drag Brown to the ground and the United centre-half believes the incident prevented him from being in a position to block Terry's effort.
"I don't think the referee played well and we've been let down by that goal," Brown told MUTV. "The decision to award the free-kick was harsh.
"Then Drogba was holding me and pulling me down, obstructing me from challenging for the ball when the free-kick came in the box. The ref didn't see that either - what can we do about it?"
The Premier League champions produced a much-improved performance compared to recent weeks and Brown acknowledged losing in West London is a bitter pill to swallow.
He added: "It's very hard to take, we played really well.
"I thought we played really well as a team and passed the ball brilliantly. We were the better team and had more chances.
"We should have done better with our chances, but we definitely didn't deserve this result and it's tough because we go home with no points."
With Rio Ferdinand injured, and Nemanja Vidic on the bench, Brown continued his partnership with Jonny Evans and he was happy with the display.
"We were fine," continued Brown. "I thought we played well as a back four and I thought we limited them to very few chances.
"In that sense, we felt like we did our jobs, which makes it worse when they score a goal like that. It's disappointing.
"We just have to keep going and try to put this behind us. We need to carry on playing as we did today, but just add goals to the performance."