Paris - American 13th seed Madison Keys proved too strong for Kazakhstan's Yulia Putintseva on Tuesday as she reached the French Open semi-finals for the first time.
The 23-year-old, who lost to compatriot and good friend Sloane Stephens in last year's US Open final, could next face a repeat of that match at Flushing Meadows after a 7-6 (7/5), 6-4 victory over world number 98 Putintseva.
The 10th-seeded Stephens takes on Russian Daria Kasatkina in the second women's quarter-final later on Tuesday.
"I really just had to focus because Yulia was playing so well, I knew I just had to make a few more balls," said Keys, who is yet to drop a set in the tournament.
Putintseva made the first significant move with a break in the seventh game, but failed to serve out the set as Keys found her range.
The Kazakh showed great resolve to force a tie-break, though, saving two set points on her own serve.
But the greater power of Keys paid dividends in the breaker, as the American finally took the opener on her fourth set point with her 18th winner.
Putintseva fought hard at the start of the second set, but Keys broke through to take a 4-3 lead with a rasping forehand return before confidently serving her way to the semi-finals.