Serena Williams was ahead, yes, but hardly at her best, when claps of thunder and a heavy downpour interrupted her third-round French Open match at a critical juncture.
So during a delay of more than 21/2 hours right before a second-set tiebreaker Saturday against 26th-seeded Kristina Mladenovic of France, Williams met with coach Patrick Mouratoglou.
"I spoke 10 minutes, which is far too long. . . . A long speech is not a good speech; it has to be short and powerful," Mouratoglou recounted later. "My point was just to make her think the way she thinks when she's good, when she's playing like Serena plays."
Coming out of the locker room determined to dictate play more than she had, Williams edged Mladenovic, 6-4, 7-6 (10), to set up a fourth-round matchup against a woman whose coaching consultant is the 34-year-old American's former rival, Justine Henin.
"Until that point, I had not been playing my game. I was playing really defensive. It's not me," said the top-seeded Williams. "So I just wanted to be Serena out there."
Her sister Venus, seeded No. 9, beat France's Alize Cornet, 7-6 (5), 1-6, 6-0, to reach the fourth round for the first time since 2010. And another American, No. 15 Madison Keys, got that far at Roland Garros for the first time with a 7-6 (3), 6-3 victory over Monica Puig.
Quarterfinal berths will be at stake in these matchups Monday: Venus Williams vs. No. 8 Timea Bacsinszky, Keys vs. Kiki Bertens, No. 12 Carla Suarez Navarro vs. Yulia Putintseva.
Next up for Serena Williams is No. 18 Elina Svitolina of Ukraine, who beat 2008 French Open champion Ana Ivanovic, 6-4, 6-4.
Svitolina, 21, has been working with Henin, a seven-time major champion whose playing career ended in 2011, on the mental aspects of tennis.
Williams and Henin played each other 14 times, Williams winning eight. Their most infamous encounter came at the 2003 French Open: There was a flap over whether Henin tried to call time out, and Williams drew fans' ire by arguing line calls. Henin's three-set victory ended a 33-match Grand Slam win streak for Williams, who was jeered off the court and cried afterward.