SHANGHAI (AP) -- Juan Martin del Potro overcame 22 aces from Germany's Philipp Kohlschreiber to advance to the third round of the Shanghai Masters with a 3-6, 6-3, 7-6 (4) victory on Wednesday.
The sixth-seeded Argentine is coming off a win at the Japan Open last week and is trying to secure his spot in the ATP Tour Finals in London.
Kohlschreiber hit 50 winners to 29 for del Potro and broke the Argentine as he served for the match at 5-4 in the third set. But del Potro raced out to a 5-2 lead in the tiebreaker and held on for the win.
In other matches, seventh-seeded Jo-Wilfried Tsonga advanced with a 6-3, 6-2 win over Spain's Pablo Andujar, while American John Isner was ousted by Argentina's Carlos Berlocq 6-4, 7-6 (4).