I've not even practiced free-kicks, admits David Luiz

Chelsea defender David Luiz revealed that his exceptional free-kick against Liverpool on Tuesday came in spite of him struggling with a knee injury in training.

The Brazil international blasted home from 25 yards to put the Premier League leaders ahead at Anfield before Georginio Wijnaldum equalised in the second half to force a 1-1 draw.

David Luiz took advantage of a loss of concentration from the defensive wall and goalkeeper Simon Mignolet to fire a dipping shot into the corner, earning praise from Liverpool manager Jurgen Klopp in the process.

The centre-back feels that the element of surprise was key and said he had not even been able to practice recently due to fitness concerns.

"I think sometimes you need to try to surprise," he told BT Sport. "I'm not in the best moment to take free-kicks because I'm not very good with my knees so not training so much

"I think free-kicks are automatic and you need practice but sometimes in the game you have to feel the game and see the opportunity."

Klopp could only praise the accuracy of the strike and said Mignolet would have struggled to save it even if he had been prepared.

"That was world class," he said. "He [Mignolet] was obviously surprised. Maybe if he's not surprised he can save it but even then it is very difficult because it is really in the corner."

Chelsea striker Diego Costa missed a penalty in the second half but the result was enough to send the leaders nine points clear at the top, with Arsenal suffering a shock 2-1 home defeat to Watford and Tottenham being held to a 0-0 draw at Sunderland.

"It's never easy to come here," said David Luiz. "In the end if you look at everything it was a good result

"I think both teams had an amazing game. Like I said, it is hard to play here.

"The crowd is amazing. This atmosphere… when you are a footballer you have to enjoy playing these kind of games."