Serena Williams needed five match points after waiting out a rain delay of more than 2½ hours, but she eventually moved into the fourth round of the French Open with a 6-4, 7-6 (10) victory over 26th-seeded Kristina Mladenovic of France.
In a tight, well-played match at Court Philippe Chatrier, action was suspended when a thunderstorm arrived right before Williams and Mladenovic began the second-set tiebreaker.
Once they resumed, Williams erased one set point for Mladenovic at 9-8 with a swinging forehand volley winner. Four times, Williams was a point from victory in the tiebreaker — at 6-5, 7-6, 8-7 and 10-9 — and couldn't close it out. But on the fifth opportunity for Williams, Mladenovic pushed a forehand wide to end the match.
Meanwhile, in her seven previous matches with Ana Ivanovic, Elina Svitolina had only managed to win a set.
She had also lost twice at Roland Garros against the 2008 champion.
The 18th-seeded Ukrainian ended that winless run on Saturday, downing Ivanovic 6-4, 6-4 on the Parisian clay to return to the fourth round.
The 21-year-old Svitolina, who had won just one match on clay this season before starting her campaign in Paris, said she played with a "better mentality" than during her previous matches against the Serb.
The Belgian's knowledge of Serena Williams' game may be a strong asset too, as Svitolina will be up against the top-ranked American in the next round. Williams, the No 1 seed, is trying to become the first woman to win consecutive titles at Roland Garros since Henin took three in a row from 2005-07.
"It's going to be a big challenge for me," said Svitolina, who has lost her three previous matches with Williams. "I think mentally I need to stay strong, stay positive, and no more junior mentality and junior tennis."
The 14th-seeded Ivanovic managed to hold just three times when serving and got broken seven times by Svitolina. She also hit 29 unforced errors.
Also advancing to the fourth round on Saturday were No 8 seed Timea Bacsinszky, who beat Pauline Parmentier 6-4, 6-2, and No. 12 Carla Suarez Navarro.
In the men's draw, Dominic Thiem prevailed in the duel of rising tennis stars, downing teenager Alexander Zverev 6-7 (4), 6-3, 6-3, 6-3.
Thiem's next opponent will be Marcel Granollers, who advanced without playing thanks to Rafael Nadal's withdrawal with a wrist injury.
Former French Open runner-up David Ferrer also reached the fourth round, for a sixth consecutive year.
The 11th-seeded Ferrer came out on top from an all-Spanish match with Feliciano lopez, winning 6-4, 7-6 (6), 6-1. He'll next face either seventh-seeded Tomas Berdych or Pablo Cuevas.
Paes-Hingis advance
India's leander Paes and his Swiss partner Martina Hingis moved a step closer to their first French Open crown together as they breezed into the mixed doubles quarterfinals after dispatching fourth seeds Yaroslav Shvedova and Florin Mergea.
Unseeded Paes and Hingis, who won three Grand Slams together in 2015, erased a one-set deficit to eke out a 2-6 7-5 10-6 win over a formidable combination in the rain-hit second round.