New York, Sep 6 (DPA) Roger Federer recovered from a stuttering start to finally beat Lleyton Hewitt for the 14th time in succession, posting a 4-6, 6-3, 7-5, 6-4 victory into the fourth round of the US Open Saturday.

'The way I came through, I was very happy, because I knew that being down a set against Lleyton is always going to be a difficult situation for me to be in,' said Federer. 'Make one more mistake and I'm in the fifth set maybe, or I go down completely. So I was relieved coming through.'

Fourth seed Novak Djokovic battled to overcome American qualifier Jesse Witten 6-7 (2-7), 6-3, 7-6 (7-2), 6-4, while Czech number 15 Radek Stepanek beat German Philipp Kohlschreiber 4-6, 6-2, 6-3, 6-3.

Djokovic, the 2007 finalist, struggled through a match containing 15 breaks of serve, taking nearly three and a half hours to advance into the second week.

'Those matches have to appear sometime during the tournament,' said the Serb. 'Maybe the good thing is that I have played this match in the third round. I have high ambitions for this tournament.'

American journeyman Witten, who returns to the Challenger circuit next week in Tulsa after his big adventure, rallied from 5-2 down in the opening set, winning in a tiebreaker before the seed slowly took control against a player appearing in only his second major.

Top seed Federer kept his bid for a record sixth straight title at Flushing Meadows alive as he made a second-set recovery to turn the tide.

But for a few moments, the world number one looked almost human on court, letting go of a 4-2, 40-0 lead in the opening set as Hewitt suddenly seized momentum.

After winning the first set with breaks of Federer's last two serve, the top seed suddenly found some of the fire in his lethal game to slowly cut down on his mounting unforced errors and eventually run out the winner.

But it was far from straightforward, with Federer wasting a 30-0 lead as he served for victory, with Hewitt clawing one of two breaks back for 3-5.