French fifth seed Jo-Wilfried Tsonga became the first major casualty of the US Open on Thursday when he slumped to a 6-4 1-6 6-1 6-3 defeat to unheralded Slovak Martin Klizan but five-time champion Roger Federer advanced with an emphatic victory.
Tsonga, who made the quarter-finals in 2011, had come into the final grand slam event of the season in a fog of injury and form worries summed up by having to skip the Cincinnati event after cutting his knee on a fire hydrant.
His defeat was good news for British third seed Andy Murray, the Olympic champion, who had been due to face the Frenchman in the semi-finals.
Left-hander Klizan, the world No.52, progressed to the third round of a Grand Slam for the first time and will tackle either 32nd seed Jeremy Chardy of France after he downed Australia’s Matthew Ebden.
Klizan only won his first career Grand Slam match this year at the French Open, spending most of his time on the second-tier Challenger tour where he won four titles this season.
But he shrugged off that inexperience, firing 32 winners to help offset the 42 unforced errors he sent down in a daring display of attacking tennis.
Top seed Federer reached the third round with an easy 6-2 6-3 6-2 win over Germany’s Bjorn Phau.
World No.1 Federer will tackle Spain’s Fernando Verdasco, whom he has beaten four times in four matches, for a place in the last 16.
Federer, bidding to become the first man to win six New York titles in the Open era, clinched the 90-minute match with his 15th ace after also firing 44 winners past the 32-year-old Phau, the world No.83.
Thursday’s meeting was the third between Federer and Phau, 13 years after their first clash in Washington in 1999, which was won by the German.
Japan’s Kei Nishikori powered his way into the third round and Tsonga’s upset loss brightened his chances for another deep Grand Slam run.
Nishikori, seeded 17th, advanced to the third round with a 6-2 6-2 6-4 victory over American Tim Smyczek.
Nishikori, among a record four Japanese men in the US Open main draw, became the first Japanese man in the Open era to reach the Australian Open last eight this year. He also reached a career-high ranking of 16th in March.
The 22-year-old Asian standout will next face Croatian 12th seed Marin Cilic, who dispatched Germany qualifier Daniel Brands 6-3 6-2 5-7 4-6 7-5.
Cilic has spent seven hours and 37 minutes on the court in winning two five-set marathons while Nishikori has yet to drop a set.
Tsonga’s upset loss means Cilic and Nishikori are the highest-ranked players in their portion of the draw with the winner likely to face Olympic champion, British third seed Andy Murray, in the quarter-finals.
In other men’s matches, Spain’s Nicolas Almagro (11th seed) beat German Philipp Petzschner 6-3 5-7 5-7 6-4, Czech Tomas Berdych (sixth seed) downed Estonia’s Jurgen Zopp 6-1 6-4 6-2 and Canada’s Milos Raonic (15th seed) overpowered France’s Paul-Henri Mathieu 7-5 6-4 7-6 (7-4).
In a good day for the Americans, Jack Sock defeated Italy’s Flavio Cipolla 6-2 6-2 6-4, Mardy Fish (23rd seed) beat Russian Nikolay Davydenko 4-6 7-6 (7-4) 6-2 6-1, Sam Querrey (27th seed) outclassed Spaniard Ruben Ramirez Hidalgo 6-3 6-4 6-3 and James Blake thrashed Spain’s Marcel Granollers (24th seed) 6-1 6-4 6-2.
Spain’s Feliciano Lopez (30th seed) survived after an epic battle against compatriot Pablo Andujar to triumph 6-4 6-1 6-7 (5-7) 3-6 7-5.
Frenchman Gilles Simon (16th seed) recorded a 6-4 4-6 6-4 6-4 triumph over Taiwan’s Jimmy Wang.