Russian Igor Andreev opened the Winston-Salem Open with an upset, blasting by second seeded Austrian Jurgen Melzer 7-5, 6-3 on Monday to reach the second round of ATP Tour's newest tournament.
World number one Roger Federer will start his bid for a 16th grand slam title against 36th-ranked Russian Igor Andreev in the first round of the Australian Open next week.
Ninth seed Gilles Simon booked his place in the third round of the Cincinnati Masters on Tuesday after a 7-6, 6-7, 6-1 win over Russian Igor Andreev.
World number one Rafael Nadal held off a strong challenge from Portugal's Frederico Gil on Monday to win 7-5 6-3 and book a place in the fourth round of the Sony Ericsson Open.
The two will clash for the third time this year at the Indian Wells semi-final
Juan Carlos Ferrero became the first seeded casualty at the US Open after he was beaten by fellow Spaniard Feliciano Lopez.
The third seed was beaten in the first round of the French Open for the fourth time in his career, ousted by Russian Igor Andreev.
The defending champion beat Russian Igor Andreev in straight sets at the Tata Open tennis championship.
Federer has now gone a complete year since he last lost a match in the final of a tournament.