MONTERREY, Mexico - Defending champion Garbiñe Muguruza nearly let a a big lead slip in the Abierto GNP Seguros quarterfinals, but recovered just in time to upend Kristina Mladenovic in straight sets, 6-1, 7-6(5).

In the pair's first meeting since a dramatic fourth round encounter at the 2017 French Open, where Mladenovic dethroned defending champion Muguruza in front of her home crowd, the Spaniard was unrattled by a late charge from the former Top 10 player this time.

Despite holding a 6-1, 5-1 lead in the match overall, Muguruza was unable to convert on four initial match points, and later needed to break the Frenchwoman at 6-5 to earn herself a chance at winning the match in two sets. 

Once in the tiebreak, the No.2 seed fell behind early, as Mladenovic struck two of her seven aces for the match, but sealed the match on her sixth match point to advance to a meeting with No.8 seed Magdalena Rybarikova.

"Being calm, having good tactics and being competitive [was the key today]," Muguruza said on-court after the match.

"It's a great position to come here defending the title. It's a good feeling, pressure at the same time, but I'm in the semifinals, so it's going well."

The pair had contrasting second-round victories, with Mladenovic dropping just two games to lucky loser Greta Arn, and Muguruza needing nearly three hours to defeat Russia's Margarita Gasparyan, but it was the Spaniard who quickly wrestled control of the match.

Despite hitting one more winner than Muguruza with nine overall, Mladenovic also hit four more unforced errors in the opening seven games with 12. 

The Spaniard converted on three of the four break points she held in the opening set, but surrendered serve herself to start the second set, giving Mladenovic her first lead since she held serve to open the match.

Muguruza would win five straight games from that point on, but more than one plot twist was to come the former World No.1's way before she returned to the semifinals.

The No.2 seed was unable to serve out the match at either 5-1 or 5-3 in the second set, and Mladenovic ran off five straight games to give herself an opportunity to serve for the set.

Nonetheless, Muguruza hit two return winners, including a backhand up the line to seal the break that sent the set to a tiebreak, to keep herself in the second set, and held her nerve in the key moments of the decisive tiebreak. 

More to come...