Novak Djokovic: "It could have gone either way"

Novak Djokovic has admitted that he could have easily been beaten by Andy Murray following his victory over the Scot at the ATP World Tour Finals.

The world number one all but sealed his place in the last four of the competition on Wednesday as he came from a set down to win in three sets against his rival.

"We really pushed each other until the end. Until the last ball went out I wasn't sure if I was going to win the match," the Serbian told Sky Sports News.

"It could have gone either way. Andy is a great player and it was enjoyable to be part of this match."

Djokovic has now won both of his matches at this year's tournament.