Mauresmo won the match with a deep forehand that Schnyder couldn’t handle and raised her arms in triumph.
The former No. 1 player in the world is trying to round into form before next week’s U.S. Open after battling rib and muscle injuries that sidelined her for several weeks after losing to Serena Williams in the third round at Wimbledon.
Mauresmo, from France, also played a tough three-set match Tuesday in the first round against Kaia Kanepi.
“These kinds of matches for the last year or so I was losing them,” said Mauresmo, a two-time Grand Slam singles champion. “At some point it makes a difference, because you have confidence from these kind of matches and you build up from there.”
Mauresmo is now ranked No. 33 in the world. The 29-year-old will face fourth-seeded Agnes Szavay of Hungry in the women’s quarterfinals. The two have never played each other.
Top-seeded Anna Chakvetadze also moved into the quarterfinals, rolling past Casey Dellacqua of Australia 6-4, 6-4 despite 11 double faults in her second round match.
“I lost my rhythm a little bit on my serve because of the wind in the first set,” Chakvetadze said. “I couldn’t find it in the second, as well. But still, I was fighting to the end and I’m pleased with this win.”
Chakvetadze, ranked No. 8 in the world, is looking for her second WTA Tour title this year. She won the Paris indoor title earlier this year and advanced to her fourth quarterfinal this season.
The men’s top seed, Fernando Verdasco of Spain, had little trouble with Ivo Minar of the Czech Republic, winning his third-round match 6-3, 6-1.
Verdasco is making his fourth appearance at the Pilot Pen. He reached the quarterfinals in 2005 and 2007.
“I am so happy with my level of play today,” Verdasco said. “I always play well here in New Haven and I am hoping to play my best.”
Luka Gregorc of Slovaki upset the men’s No. 2 seed, Ivo Karlovic, 7-6 (4), 4-6, 6-2 in their third-round match.
American Robby Ginepri’s run at the Pilot Pen also ended. Mischa Zverev of Germany defeated Ginepri 1-6, 6-3, 6-1 in their third round match.
ALSO ON THIS STORY Discuss: Sound off on tennis message boards
WORLD MATCH PLAY SET FOR CHANGE
Mauresmo struggles to victory at Pilot Pen