Serena Williams is ready to go the distance with Tsvetana Pironkova again at a grand slam after clearing the first hurdle in her bid for French Open glory.
Williams, who turned 39 on Saturday, took her time to warm up on a cool Monday in Paris, Kristie Ahn making life particularly difficult for the sixth seed in a well-contested opening set.
The American duo had also met in the opening round of the US Open and - as was the case in New York - the favourite eventually prevailed in straight sets,meaning a clash with another familiar foe next.
Pironkova threatened to cause an upset when they did battle in the quarter-finals at Flushing Meadows earlier this month, though faded down the stretch to lose in three.
Still, Williams - chasing a 24th slam to move level with Margaret Court's record - expects another tough test from the Bulgarian, who defeated Andrea Petkovic 6-3 6-3.
"She's playing well, but I am too. I'm ready to play her. She'll be ready to play me," the three-time French Open champion said in her post-match press conference.
"It will be a long match, she will get a lot of balls back, but so am I. I'll be ready."
Williams revealed she was a little flat against Ahn in a first set that went to a tie break, before a more positive approach allowed her to breeze through the second without dropping a game.
"The biggest difference was just confidence. I just need to play with more confidence, like I'm Serena," she said. "So that was it. I just started playing like that. And I love the clay and I started playing like it, opening the court and moving and sliding."
SUCCESS FOR SEEDS ON DAY TWO
Three other top-10 seeds at the tournament avoided early exits. Elina Svitolina, Kiki Bertens and Petra Kvitova prevailing, though none of the trio had it all their own way.
Bertens was in danger of going home early when the fifth seed fell a set behind but rallied impressively to see off Katarina Zavatska 2-6 6-2 6-0.
Seventh seed Kvitova overcame Oceane Dodin 6-3 7-5, though admitted afterwards her opponent had made her work for the win.
"You know, she didn't make that many mistakes and it was really a tough one," Kvitova - a semi-finalist at Roland Garros in 2012 - told the media. "I just really tried to stay there mentally strong and wait for the chance to break her and serve well."
Meanwhile, Svitolina, the third seed, triumphed 7-6 (7-2) 6-4 against Russian Varvara Gracheva.
KEYS LOST IN FRENCH CAPITAL, KERBER CRASHES OUT
Madison Keys, the 12th seed, was on the wrong end of an upset, the American beaten in straight sets by Zhang Shuai.
Prior to that match on the same court, 15th seed Marketa Vondrousova was crushed by Iga Swiatek of Poland, winning just three games in a surprisingly lopsided contest that spanned just 63 minutes.
Angelique Kerber also suffered a shock exit, the three-time major winner going down 6-3 6-3 to world number 102 Kaja Juvan.
Karolina Muchova was also dumped out, going down to Christina McHale, but 2016 champion Garbine Muguruza avoided a similar fate against Tamara Zidansek, overcoming a one-set deficit to eventually prevail 5-7 6-4 8-6.