Fourth-seeded Andrea Petkovic of Germany rallied to defeat third-seeded Flavia Pennetta 1-6, 6-4, 6-3 Sunday in the final of the season-ending Tournament of Champions, clinching her third WTA title of the year.

Pennetta started aggressively with the Italian breaking Petkovic's serve three times to win the opening set in just 35 minutes.

Petkovic staged a comeback in the second set thanks to her booming serve. The German earned the only break in the first game and held on to close the set.

Petkovic's better physical condition was decisive in the third set. She broke Pennetta's serve at 3-3 and cruised from there.