MONTERREY, Mexico -- Defending champion Garbiñe Muguruza of Spain bumped up her winning streak at the Abierto GNP Seguros to seven straight matches after a tough 6-3, 6-7(1), 6-2 victory over Margarita Gasparyan of Russia, advancing to the quarterfinals in Monterrey.

After the match, Muguruza told the press that it was a "good battle. I mean, [Gasparyan] played great. I think I could level my game -- I was hoping that if I stay calm, I could play better and better, and I managed to win."

Photos: Monterrey magic: From Bartoli to Muguruza

In the first meeting between the two competitors, World No.19 Muguruza came back from an early break down in the final set, reeling off the final six games of the encounter to dispatch her 75th-ranked competitor in a grueling two hours and 39 minutes.

"I just tried to think a little bit smarter, use more tactics," said Muguruza, when discussing her final-set fight. "I just managed to do it and really turned it around."

The Spaniard played aggressively throughout the match, with 40 winners and 46 unforced errors, while the Russian had 27 winners to 30 miscues. Each player had 14 break points in the tilt, but Muguruza converted six of those chances, while Gasparyan only converted three.

No.2 seed Muguruza will face No.7 seed Kristina Mladenovic of France in the quarterfinals. Mladenovic dispatched lucky loser Greta Arn of Hungary, 6-0, 6-2, earlier on Thursday. Mladenovic leads their head-to-head on the WTA by 2-0.

"We’ve known [each other] since we’re very young, in juniors and stuff," Muguruza said of Mladenovic. "So it’s going to be a good match, I’ve played her before and it’s a good quarterfinal."

Muguruza had to fend off two break points in her opening service game, but from that juncture forward, the Spaniard had smooth sailing in the first set. Muguruza clinched the first service break of the encounter, after Gasparyan pushed a forehand into the net on break point to give up the 3-1 lead to the defending champion.

Gasparyan’s powerful hitting matched Muguruza’s for the remainder of the opener, but the Russian was never able to get an opportunity on the Spaniard’s serve beyond her initial chances in the first game. Muguruza played precise, clean tennis, reaching set point at 5-3 with a service winner, and forcing an error with a sturdy backhand to grab the one-set lead.

But the second set was far more challenging. It was Gasparyan who claimed the initial break of serve, as the unforced errors off of the racquet of Muguruza mounted. Gasparyan had break points to extend her lead to 5-1, but Muguruza used pinpoint accuracy to evade those problems and hold on for 4-2.

Three service breaks in a row followed, as the duo blasted rocketing groundstrokes at each other, ending with Muguruza back on serve at 5-4. Powerful serving by Muguruza helped her stop the string of breaks and hold for 5-5, and two games later, the players moved into the tiebreak.

In the breaker, Gasparyan took early control as Muguruza misfired on her forehand, giving the Russian a 3-0 lead. More unforced errors from the Spaniard handed Gasparyan a commanding 6-1 lead, and the Russian closed out the second set in style, with a thunderous ace.

Gasparyan broke out ahead in the decider, using her powerful forehand to force an error on break point of the first game. The Russian then fended off four break points in the following game before using tremendous defense to hold serve for 2-0 and keep her nose in front.

But the wind went out of the Russian’s sails after that difficult game, while Muguruza recovered the range on her shots. The Spaniard broke to level the set at 2-2 with a stirring backhand winner down the line, and earned a second break at love to lead 4-2.

Muguruza staved off two break points to hold for 5-2, as her stellar serving returned in the nick of time to finish off that game. Finally, a third straight break and sixth straight game went the Spaniard’s way, using a backhand to force an error on her third match point and wrap up a lengthy tussle with Gasparyan.