TORONTO (AP) ― World No. 1 and defending champion Caroline Wozniacki lost to Roberta Vinci 6-4, 7-5 in a second-round match at the Rogers Cup on Wednesday.

Wozniacki, who has won a WTA-leading five titles this year, was up 5-1 in the second set and looking to rally from a set down. However, the No. 22-ranked Italian stormed back with three break points to complete the upset.

Also, former No. 1 Serena Williams and fifth-seeded Maria Sharapova both survived scares to advance.

Williams pulled out a tough second set to beat Julia Goerges 6-1, 7-6 (7), and Sharapova edged 19-year-old Bojana Jovanovski of Serbia 6-1, 7-5 in a chilly evening match.

Williams, a 13-time Grand Slam tournament champion, used her intimidating serve, which topped out at nearly 122 miles per hour, to roll through her first set before the 20th-ranked German fought back in the second.

Wozniacki had a bye in the first round and never really got going against the 22nd-ranked Italian, sending her return long on match point. Wozniacki also hit returns long twice at the first set point.

“I would have liked to have won that one and especially after leading 5-1 in the second,” Wozniacki said. “It’s not fun to lose this, but there’s nothing really I can do about it now, just practice, and try to do better.”

Windy conditions wreaked havoc with Wozniaki’s serve in the first set, as the ball repeatedly floated away when she tossed it above her. She had seven double-faults in the match.

“It was very difficult at first with the wind,” Wozniacki said. “Especially when you threw it up. It was going everywhere, so definitely that didn’t make it easy. It was blowing in different directions, but it’s the same for both players.”

Nadal knocked out

Rafael Nadal is out at the Rogers Cup after a shocking 1-6, 7-6 (5), 7-6 (5) defeat in the second round against Croatia’s Ivan Dodig on Wednesday night.

With the tiebreaker in the final set tied 5-5, Dodig ― ranked 41st in the world ― ripped a 135 miles-per-hour ace past Nadal, then finished the upset by hammering a backhand that the second-ranked Spanish star couldn’t handle.

Dodig, who had 19 aces in the match, will face Serbia’s Janko Tipsarevic in the next round. Tipsarevic beat Spain’s Fernando Verdasco 6-4, 7-6 (5), 6-3.

Earlier, Roger Federer defeated Vasek Pospisil of Canada 7-5, 6-3.