Top seed Roger Federer booked his place in the last 16 of the US Open with a 6-3 7-6 (8/6) 6-2 victory against Olivier Rochus at Flushing Meadows.
The world number one’s victory against the 27th seed extended his winning streak to 21 matches overall.
The Swiss ace won in straight sets for the third time in as many matches and has dropped just one set in his last eight Grand Slam matches, but is determined not to be complacent.
“I don’t like to think about I’m number one and that he’s not going to try,” Federer said. “That can work against you. They can come out and want to win and may play better than they usually do.”
Federer now meets unseeded Nicolas Kiefer after the German advanced to the fourth round for the second consecutive year with a 6-4 6-7 (5/7) 6-4 6-1 victory over Arnaud Clement.
The Frenchman had knocked out Britain’s Andy Murray in the last round in a thrilling five-setter but had no answer to Kiefer’s power.
Australia’s Lleyton Hewitt advanced to the fourth round after a thrilling five-set victory against Taylor Dent.
The third seed trailed by two sets to one and was in trouble against the big-serving American but raised his game in customary fashion to seal a 6-3 3-6 6-7 (2/7) 6-2 7-5 victory in three hours and 21 minutes.
The 2001 winner at Flushing Meadows now meets Dominik Hrbaty of Slovakia, who beat Spain’s David Ferrer 6-7 (7/9) 7-5 7-5 7-5.
The best match of the day was an unlikely classic between Italy’s Davide Sanguinetti and Thailand’s Paradorn Srichaphan.
Sanguinetti outlasted Srichaphan, who suffered cramps, 6-3 4-6 6-7 (2/7) 7-6 (7/6) 7-6 (7/5) in a match that lasted four hours 24 minutes – the longest in the tournament so far.