World number one Novak Djokovic has claimed that his five-set victory over Roger Federer in the semi-final of the US Open yesterday was one of the "biggest wins" of his career.

The Serbian trailed Federer by two sets and and saved two match points before mounting a comeback against his Swiss opponent to advance through to the final against Rafael Nadal tomorrow.

"It was definitely the biggest win of this year, one of the biggest wins of the career, under the circumstances," Djokovic told a press conference.

"I was two sets down. Roger was in control, he was playing better and then I switched gears and I managed to play much better in three sets."

Djokovic, 24, has reached three US Open finals but has never claimed the trophy.