NEW HAVEN, Conn. (AP) American Alison Riske upset sixth-seeded Italian Flavia Pennetta 6-1. 7-6 (3)Tuesday in the second round of the Connecticut Open, the final tuneup on the Women's Tennis Association Tour before the U.S. Open.
Riske, the only American left in the tournament, broke Pennetta's serve four times while cruising through the opening set.
Pennetta, ranked No. 12 in the world, suffered from a bout of dizziness and saw a trainer and a doctor in between sets, but was able to bounce back from a 3-1 deficit to force the second-set tiebreaker.
Riske is ranked 44th in the world and came into the tournament on a 3-match losing streak before beating Australian Casey Dellacqua in the opening round.
Top-seed Simona Halep and Wimbledon champion Petra Kvitova each had matches scheduled later Tuesday.