US Open, Flushing Meadows
Dates: 30 August - 12 September Start time: 1600 BST
Coverage: Live text commentary on BBC Sport website and mobiles; updates on BBC Radio 5 live; live on Sky Sports
Roger Federer overcame windy conditions to beat Andreas Beck 6-3 6-4 6-3 and reach the US Open third round as two big seeds crashed out on day four.
The five-time champion raced to 5-0 and finally took the first set after the lively German clawed back three games.
Beck, ranked 104, kept battling but the world number two proved too strong.
Maran Cilic, 11th seed, lost over five sets to Japanese qualifier Kei Nishikori, while Richard Gasquet beat sixth seed Nikolay Davydenko.
Fifth seed Robin Soderling had few problems on Grandstand as he needed just 92 minutes to crush American Taylor Dent 6-2 6-2 6-4.
Russian Davydenko, a 2006 and 2007 US Open semi-final loser to Federer, was brushed aside 6-3 6-4 6-2 by the 38th-ranked Gasquet, one of a record 12 Frenchmen to reach the second round.
Tougher matches will only be coming up now, I guess. I underestimate nobody
The ATP World Tour Finals champion, still struggling for form after missing 11 weeks earlier this year because of a broken left wrist, rarely threatened the former top-10 player who lost only seven of 52 points on his first serve.
Gasquet completed his rout in one hour 53 minutes and will next face South Africa's Kevin Anderson or Brazilian 26th seed Thomasz Bellucci.
The longest match of the week was not a happy one for Croatian Cilic, who reached his first Grand Slam quarter-final at last year's US Open, as he lost over five sets to Nishikori in a battle that lasted a minute short of five hours.
This year's Australian Open semi-finalist started strongly and edged a nervy opening set before losing a tie-break in the next set which went on for 77 minutes.
The 20-year-old rising Japanese star, whose win was his fifth this week including qualifying, battled back from trailing 2-1 in sets to come through and win 5-7 7-6 (8-6) 3-6 7-6 (7-3) 6-1.
"I'm pretty tired of course," Nishikori said. "I was cramping from the second or third set but I kept fighting and fighting and that fourth set tie-break was key for me.
"It was a great match. It was hot but I am feeling great now."
Nishikori will next face Spanish 21st seedAlbert Montanes, who defeated Australian wildcard Carsten Ball 6-4 6-3 6-1.
Fededer was unable to produce the fireworks and fluidity of his first-round win over Brian Dabul, but his 15 aces and calmness when Beck did occasionally put him under pressure were enough to guide him through in straight sets.
"It's the perfect start, sure," said Federer. "I played Monday, had two days off. I had another easy one physically today and here I am in the third round feeling like I'm completely in the tournament.
"Obviously they weren't the most difficult matches. I didn't have to save multiple break points or whatever. Even though I got broken today, I feel really good. Tougher matches will only be coming up now, I guess. I underestimate nobody."
The 29-year-old Swiss has now racked up 42 wins in his past 43 matches at Flushing Meadows, and with Andy Roddick and Lleyton Hewitt both out, Federer is the only previous winner of the US Open left in the men's field.
After the 16-time Grand Slam won the opening five games against Beck he then struggled to contend with the wind on Arthur Ashe and allowed the 24-year-old to hit back.
But despite conceding three successive games, Federer rallied to take the first set and after just one hour and 41 minutes he had booked a third-round spot against Paul-Henri Mathieu, who overcame French compatriot Guillaume Rufin 7-6 (7-3) 6-4 6-3.
Austrian Jurgen Melzer, the 13th seed, battled to a 6-4 6-7 (4-7) 6-3 1-6 7-5 win over Ricardas Berankis of Lithuania.
The Flushing Meadows crowd had much to cheer about on Louis Armstrong as 19th seed Mardy Fish, a recent finalist at the Cincinnati Masters, fired 14 aces on his way to an impressive 7-5 6-0 6-2 win over Uruguay's Pablo Cuevas.
The American will next face France's Arnaud Clement, who led 6-3 5-5 when Argentina's Eduardo Schwank retired with an ankle injury.
Fish said: "I've never put myself in position to be a guy who is talked about at a Grand Slam. I'd love another crack at a top-five top-10 player in a Slam. I've beaten a couple but not deep into a tournament."
Fellow American James Blake beat Peter Polansky of Canada 6-7 (1-7) 6-3 6-2 6-4, while Spain's 22nd seed Juan Carlos Ferrero defeated Ricardo Mello of Brazil 6-1 6-4 6-4.