Federer battles hard to beat Monfils in five-set thriller to advance to US Open semis

17-time Grand Slam champion Roger Federer had to battle hard to beat Gael Monfils in a five-set thriller to advance into the US Open semifinal and keep alive his hope of an 18th Grand Slam title.

The Swiss saved two match points as he won 4-6, 3-6, 6-4, 7-5, 6-2 in a dramatic New York night session to reach the semi-finals. He will next face Croatia's Marin Cilic in the last four on Saturday.

Federer, on falling two sets behind, said that he still thought the finish line was far for Monfils, and added that he knew that the Frenchman could play better tennis, The BBC reported.

The Swiss tennis ace said that when he was down two match points, that's when he wasn't feeling too good any more. He added that he thought 'this is it, don't let Monfils have an easy shot, and go down fighting.'

But Federer added that he served well and managed to turn it around.

Federer said that it is just unbelievable to win matches like this at Slams. He added that he is not sure that he has ever saved match point before in a Slam.