Frenchwoman Alize Cornet won nine games in a row to beat Karin Knapp of Italy 1-6, 7-5, 6-0 and Chanelle Scheepers of South Africa routed Maria-Teresa Torro-Flor 6-2, 6-1 as they both advanced to the quarterfinals of the Grand Prix SAR on Wednesday.
Corent bounced back from a set and 5-4 down and next plays either former French Open champion Francesca Schiavone of Italy or Romania's Simona Halep. Scheepers broke the Spanish player's serve seven times in her match and next meets either seventh-seeded Kristina Mladenovic of France or Yulia Putintseva of Kazakhstan.
Putintseva reached the second round after beating Mathilde Johansson of France 6-3, 6-4.
In other first-round matches, the sixth-seeded Schiavone labored past Croatia's Petra Martic 7-6 (8), 6-4 and Olga Puchkova of Russia needed more than three hours to beat Daniela Hantuchova of the Slovak Republic 3-6, 7-6 (5), 7-5.
"We were both fighting for it and it was really up and down out there, but I think I really took my chances," Puchkova said. "In the first set I think I went for too much and made some unforced errors, but then the next two sets I just focused on running for every ball and not going for too much and staying patient."
Schiavone, meanwhile, saved three set points in the first-set tiebreaker.
"I think I was playing really well until 4-1 in the first set, but I started missing some shots," Schiavone said. "It's not easy to stay focused because the ball flies a little bit, and you have to pay attention on every point."
Flavia Pennetta also reached the second round after beating Melinda Czink of Hungary 6-1, 7-6 (2), rallying from 5-1 down and hitting six aces in the second set.