Muguruza defeated the fifth-seeded Frenchwoman in their second quarterfinal in two weeks, with the Spaniard also winning last week after being a set down in Doha. On Thursday, she needed just two sets but they stretched over 108 minutes.

Muguruza next plays Darya Kasatkina, who beat Russian compatriot Elena Vesnina 7-6 (5), 6-1.

Top-seeded Elina Svitolina moved to within two matches of retaining her title with a 6-2, 6-4 win over wild card Naomi Osaka of Japan.

Waiting for Svitolina in the semifinals is the resurgent Angelique Kerber. The sixth-seeded German defeated third-seeded Karolina Pliskova 6-4, 6-3 in a 74-minute encounter.

Third-ranked Muguruza had finished her round of 16 match at 1:50 a.m. local time but, if she was tired, she did not show any effects.

The first set was evenly contested, with games going with serve. Muguruza then applied immense pressure and had three break points in the ninth game. That lasted just shy of 10 minutes; Garcia held on, but she was broken in the 11th game.

Garcia was making more mistakes because of her aggressive mindset and her tendency to go for the lines. Muguruza was solid throughout, and broke her opponent twice early in the second to go 4-1 up.

"I felt much better in this match than the one we played in Doha. It's always difficult because we played almost in the same week twice," Muguruza said. "But when you play a top-10 player, and you beat her second time in a row, it gives me a good sign that what I'm doing is right.

"I was a little bit upset because it was very late [last night]. I ended up sleeping at 4 a.m. But there's nothing I can do. I have to accept it."

Kerber secured her 15th win of the season and reached her third semifinal in four tournaments. She broke early in both sets and lost just eight points on her first serve.

The winner of two Grand Slams in 2016, Kerber did not win a single title in 2017 and dropped to No. 21 in the rankings.

"I don't know exactly what happened last year," Kerber said. "I was still trying my best."