PARIS -- Serena Williams went from a 72-minute first set that required a tiebreaker to a lopsided second set in which she did not drop a game in her first-round match at the French Open.
"I just need to play with more confidence, like I'm Serena,'' Williams said, by way of explanation for how her 7-6 (2), 6-0 victory over 102nd-ranked Kristie Ahn unfolded Monday.
This is how Ahn described the sensation of being across the net from that version of Williams, the one at her very best.
"It feels like you're trying to push a runaway train in the opposite direction,'' Ahn said. "It's very difficult to try and stop, to stop her momentum when she's going, when she's feeling it.''
Imagine Ahn's [bad] luck of the draw: She is the first player to face Williams in the first round at two consecutive Grand Slam tournaments, having also lost their matchup at the U.S. Open.
"I mean, I laughed,'' Ahn said. "I mean, what are the odds?''
Three-time Grand Slam champion Angelique Kerber lost in the first round for the second straight year. The 18th-seeded German was beaten by 19-year-old Slovenian Kaja Juvan 6-3, 6-3.
Two-time Grand Slam champion Svetlana Kuznetsova also went out. The 2009 French Open champion was beaten by Russian countrywoman Anastasia Pavlyuchenkova 6-1, 2-6, 6-1.
Garbine Muguruza could have joined Kerber and Kuznetsova. But the 2016 French Open champion held firm to beat Tamara Zidansek 7-5, 4-6, 8-6.
Among the other key results on Day 2 of a chilly, pandemic-postponed French Open were losses by 2019 runner-up Marketa Vondrousova, who was beaten 6-1, 6-2 by Polish teenager Iga Swiatek, and 2017 U.S. Open finalist and 2018 French Open semifinalist Madison Keys, who fell to Shuai Zhang 6-3, 7-6 (2).
Also Monday, fifth-seeded Kiki Bertens beat Katarina Zavatska 2-6, 6-2, 6-0, and No. 7 Petra Kvitova defeated Oceane Dodin 6-3, 7-5.
Williams now gets another rematch, facing Tsvetana Pironkova, the player the 39-year-old American beat in the quarterfinals in New York earlier this month.
"It's always exciting to face her,'' Pironkova said.
Williams has won three of her professional-era-record 23 Grand Slam singles titles in Paris; one more and she'll equal Margaret Court's all-era mark.
She keeps coming close: Williams has made it to the final at four of the past eight major tournaments, losing each time. At the U.S. Open, she exited in the semifinals against Victoria Azarenka, a match in which she was slowed a bit down the stretch after hurting her left Achilles tendon.
Williams wore a strip of black athletic tape on the lower portion of that leg Monday. Asked after the match what she's done to take care of herself, she replied: "A ton of prayer.''
The Associated Press contributed to this report.