Six-times champion Roger Federer [ Images ] was forced to dig deep at Wimbledon [ Images ] again on Wednesday, the Swiss reaching the third round with a hard-fought 6-3, 6-7, 6-4, 7-6 victory over Serbian Ilija Bozoljac.

Federer, who came back from the brink to defeat Colombian Alejandro Falla [ Images ] in his opening match, had an uncomfortable time against the big-serving qualifier.

The number one seed, in unfamiliar territory on Court One, the first time he has been away from Centre Court at the All England [ Images ] Club since 2007, finally prevailed in two hours and 46 minutes.

Federer now takes on either Frenchman Arnaud Clement [ Images ] or Australian Peter Luczak.

Meanwhile, Novak Djokovic [ Images ] withstood some rocket-fuelled Taylor Dent serving on Wednesday to move impressively into the third round at Wimbledon.

The Serbian third seed, who toiled for five sets against Olivier Rochus [ Images ] in Monday's first round, was too good for the American as he claimed a 7-6, 6-1, 6-4 victory.

Dent walloped down a serve at 148mph in the opening set, a delivery that beat the previous Wimbledon speed record of 146mph by Andy Roddick [ Images ] last year, but he ran out of steam.

Djokovic was untroubled after taking the first set on a tiebreak and completed his Centre Court victory in one hour and 57 minutes.

He will face Spain's Albert Montanes in round three.