Sir Alex Ferguson claimed referee Martin Atkinson's decisions which led to Chelsea's winning goal at Stamford Bridge were the kind which lead managers and players to "lose faith in refereeing".

Atkinson awarded a free-kick for Darren Fletcher's challenge on Ashley Cole, and Wes Brown appeared to be impeded as Frank Lampard's delivery was turned into the net.

An unhappy Ferguson told Sky Sports 1: "Clearly, Darren Fletcher's won the ball - Ashley Cole's never touched and has jumped up in the air - and then (Didier) Drogba's pulled Brown to the ground for the goal.

"The referee's position to make the decision was absolutely ridiculous, he can't see anything. He's got a Chelsea player (Joe Cole) standing right in front of him and he doesn't even move.

"It was a bad decision, but there's nothing we can do about it. You lose faith in refereeing sometimes, that's the way the players are talking in there - it was a bad one."

Ferguson stopped short of blaming Atkinson for his side's defeat, admitting instead they should have taken the chances they created.

"That goal should never have been allowed. We've dominated the game; we've had great chances to win the match - and that's our fault," he told Sky Sports 1.

"We had great opportunities to get to the edge of the box and some really good chances in and around the box, but we should be finishing it off.

"We've only ourselves to blame in that respect. But you do need a break - and we never got the break we needed."

He admitted the defeat - United's third on the road this season - was more significant than their recent 2-0 reverse at another rival club, Liverpool.

"The fact is Chelsea go five points clear of us," he said.

"The defeat to Liverpool didn't affect our position in the league - that affects our position in the sense that if we'd have won we'd have gone top today."