Alize Cornet booked a spot in the semi-finals of the Abierto Mexicano Telecel after battling to a 3-6 7-6 (12-10) 7-6 (7-2) win over Lourdes Dominguez Lino.
The third seed looked to be on her way out after falling a set and 3-0 down but fought back to edge out her Spanish opponent, saving an incredible nine match points in the process.
In the back-and-forth contest Domingez Lino secured more breaks of serve, recording 10 to Cornet's eight, but it was the Frenchwoman who eventually came through after 3 hours and 33 minutes.
"My God, I just cannot believe I won this match. I saved I don't know how many match points, I think eight - it was such a great fight, and such a great match," Cornet told the WTA's official website.
"Lourdes was one point away from having the victory many times, but I just kept fighting and stayed very focused on every point. I had to dig very deep inside of me to find the power to win this match.
"Now I really have to focus on my recovery for the semi-finals tomorrow (Friday)."
Cornet will face top seed Sara Errani in the last four after the French Open finalist completed a 6-4 6-4 victory over Kiki Bertens.
Errani was playing in the last match of the day and took an hour and 36 minutes to complete the victory, finishing the job shortly before 1am local time.