NEW HAVEN, Conn. — Four-time champion Caroline Wozniacki was upset 6-4, 6-2 Wednesday by Camila Giorgi of Italy in the second round of the Connecticut Open.

Giorgi, who beat Wozniacki in last year’s U.S. Open faced just two break points. Her first serves reached 117 mph and her second serves hovered around 107 mph. She consistently hit ground strokes at Wozniacki’s feet, preventing her from moving laterally.

The 37th-ranked Giorgi broke Wozniacki’s serve in the first game of the match and twice in the second set.

“I think today the serve was the key and really consistent,” she said.

It was the earliest exit at this tournament for the 24-year-old Dane, who has appeared in New Haven seven times. She won in each of her first four trips and lost in the semifinals in 2012 and 2013.

Wozniacki is ranked No. 11 and was seeded fourth this year. But she also has been training to run the New York Marathon while keeping up a full tennis schedule. She said the cross-training has not been a problem, but acknowledged being tired Wednesday.

“I haven’t had a day off basically since I came to Montreal, so I’ve been playing almost every day,” she said. “The tank just wasn’t full today and when you play a player like that you just don’t get by with not moving 100 percent.”

Giorgi will play Garbine Muguruza in the quarterfinals. Muguruza, ranked 26th in the world, needed three sets to dispatch of qualifier Peng Shuai of China, 6-2, 3-6, 6-3.

Muguruza dropped the first two games of the final set, but won the next five games en route to the victory.

“I was nervous because I didn’t know what to do at that point,” Muguruza said. “But I just said to myself, ‘Just continue, because she’s also going to get nervous or she’s going to miss and not continue like this.”

Just one seeded player, second-seed Petra Kvitova, has advanced to the quarterfinals of the tournament. Third-seed Eugenie Bouchard was hoping to join her. She was to face Samantha Stosur later Wednesday.

Garcia-Lopez wins

WINSTON-SALEM, N.C. — Spain’s Guillermo Garcia-Lopez battled through a third-set tiebreaker before beating 11th-seeded Donald Young of the 6-7 (4-7), 6-3, 7-6 (8-6) on Wednesday in the third round of the Winston-Salem Open.

Garcia-Lopez, the tournament’s fifth seed, overcame a 6-4 deficit in the third tiebreaker by winning four consecutive points in the final tuneup before next week’s U.S. Open.

Garcia-Lopez will next face American Sam Querrey, a 7-6 (7-4), 6-4 winner over second-seeded Kevin Anderson of South Africa, in Thursday’s quarterfinals at the Wake Forest Tennis Center.

Also advancing to the quarterfinals were Belgian qualifier David Goffin, who beat 15th-seeded Jarkko Nieminen of Finland 6-4, 4-6, 6-4;and Jerzy Janowicz, a 4-6, 6-3, 6-4 winner over Edouard Roger-Vasselin .

of France.

; ninth-seeded Yen-Hsun Lu of Taiwan beat No. 8 seed Marcel Gransllers of Spain 6-1, 6-2; and 14th-seeded Andreas Seppi of Italy downed France’s Nicolas Mahut 6-4, 7-6 (9-7).