UNHAPPY Rafael Benitez accused Antonio Valencia of taking a dive to earn a pivotal penalty as Liverpool's hopes of Champions League qualification suffered another hammer blow.

Benitez's side surrendered an early lead to slip to a 2-1 defeat at bitter rivals Manchester United yesterday and lose ground in the race for fourth place.

Fernando Torres had put the visitors ahead with a fine header in the fifth minute only for United to draw level seven minutes later when Wayne Rooney converted the rebound after Pepe Reina had saved his penalty.

Referee Howard Webb awarded the spot kick when ruling Javier Mascherano had hauled back United winger Valencia inside the 18-yard box, although television replays suggested the foul took place outside the area with Valencia falling to the ground once inside.

And Benitez said: “I do have doubts about the penalty. It made a big, big difference. That one situation changed everything.

“I've seen three replays of the incident and the last one was very suspicious. You watch the replay and you can see how he fell to the ground.

“Did Valencia dive? Yes, I think so, although it's not clear. There is maybe a contact but the way he fell down – it was strange.

“From the bench I was asking the people who were below with the television about the penalty and they said it was a penalty.

“And it wasn't a sending-off, (Jamie) Carragher was coming inside and had been in a central position.”

Ferguson suggested before the game that the authorities were biased towards Liverpool, and Benitez said: “I’m really surprised when you talk about these things the refs are professional we know about the influence of Sir Alex in everything but these referees are very professional

“When you have different opinions you have to express different opinions he has own opinion about everything.”

It's the second time in as many months that Webb has upset Liverpool, having failed to award a last-minute penalty at Arsenal following a clear handball by Cesc Fabregas.

But Benitez, whose side are now four points off the fourth and final Champions League berth having played a game more, said: “We are talking about one situation we cannot agree. I think he is a very good referee. There have been decisions against us in the past but he is professional.”