Juan Martin del Potro of Argentina received a warm ovation from fans at the Swiss Indoors tournament in Basel on Wednesday and continued his domination of the event with a 6-3, 6-4 victory over Dutch qualifier Robin Haase.
Competing in the event for the first time since beating Roger Federer in the 2013 final, del Potro recorded his 11th straight victory in Basel by winning nearly 60 percent of second-serve points. He also converted all four break points during the 82-minute match.
The 28-year-old beat Federer in 2012 and 2013 but skipped the last two tournaments due to a left wrist injury, which caused him to miss most of the last two years and began this tournament ranked No. 42.
Del Potro, who received a wild card into the tournament, will meet fifth-seeded David Goffin of Belgium, who is currently 10th in ATP points and 190 behind No. 9 Tomas Berdych. Goffin must reach the final to pass Berdych and the top eight players at the end of the season qualify for the year-end championships Nov. 13-20 in London.
In other first-round matches, eight-seeded American Jack Sock cruised past France's Adrian Mannarino 6-3, 6-3 while seventh-seeded Richard Gasquet of France retired after 36 matches in a 6-2, 2-1 loss to Argentine Guido Pella.
Sock, who lost to the Stockholm Open final to del Potro Sunday, will face Spain's Marcel Grannollers Thursday.
In a second-round match, Japan's Kei Nishikori overcame 18 unforced errors in the opening set to claim a 7-6 (3), 6-2 victory over Italy's Paolo Lorenzi. The third-seeded Nishikori improved in the second set by making only six unforced errors.