Sydney - Former US Open champion Juan Martin del Potro, returning from a wrist injury that sidelined him for much of 2010, beat sixth-seeded Feliciano Lopez of Spain 6-7 (5), 7-6 (9), 7-6 (3), in the first round of the Sydney International on Monday.
The Argentine saved a match point in the second set and finally prevailed on his first match point in the third-set tiebreaker, hitting a forehand to the open court. The match took more than three hours to complete.
Other men's winners included Germany's Florian Mayer and Ukrainian Sergiy Stakhovsky.
In women's play, French Open champion Francesca Schiavone of Italy, the No. 5 seed, was beaten by Alisa Kleybanova of Russia 6-7 (5), 6-1, 6-2.
Fourth-seeded Australian Samantha Stosur advanced to the second round with a 7-5, 6-4 win over Yanina Wickmayer of Belgium, while seventh-seeded Victoria Azarenka of Belarus beat Ekaterina Makarova of Russia 2-6, 6-2, 6-4 and eighth-seeded Li Na of China defeated Anastasia Rodionova of Australia 6-1, 6-2.
Also Monday, defending men's champion Marcos Baghdatis withdrew from the tournament due to a left groin injury suffered during a training session over the weekend.
The second-seeded Cypriot, a 2006 finalist at the Australian Open, was replaced in the main draw by a lucky loser from qualifying, Lukasz Kubot of Poland.