PARIS -- Serena Williams notched her first win over a top-20 player in the scant half-dozen singles matches she's played since returning from maternity leave, but that wasn't the most important head-to-head stat.
Every time Williams steps onto the court, she will be measured against her previous superlative self in terms of movement, timing and power. Thursday, she tapped into muscle memory and edged closer to that most familiar and formidable opponent.
Specifically, vintage Serena emerged in the second game of the second set of her second-round French Open match against Australia's 17th-seeded Ashleigh Barty. At 30-all, she cracked a forehand volley winner to earn her first break point of the evening, sank into a brief squat and let out a full-body scream as striking as her full-length body suit.
"If I were to play my former self, I'm not sure I would win," she told reporters afterward. "But I can't say I would lose. And thank God I don't have to do that. So it works out great for me.
"This is just my third tournament back, and I have had a long break since my last one, so I'm probably not where I was before I left. But the good news is, I feel like I'm definitely going to get there. And I don't want to get there, I want to get beyond there. I don't want to limit myself. That's what I want to look forward to doing."
Barty agreed. "When push came to shove, the real Serena came out," she said. "And that's one of her best assets is when her back is against the wall, the best comes out.
"I think she's not quite at the level she was when she was at her best, but that's normal. That's expected. But her level when she's not quite on her best is still bloody good."
A precocious, longtime Grand Slam doubles title contender with recently retired partner Casey Dellacqua, the 22-year-old Barty has played the best solo tennis of her career over the past season-plus. But, as she observed, she gave Williams too many chances to find and maintain rhythm Thursday after winning the first set.
"You can't give someone of Serena's caliber that many looks at second serves and put yourself under the pump that much," Barty said. "It's disappointing, because I was well and truly in the match ... at the end of the day, I gave it a crack and it wasn't enough."
Moving assertively into the court and striking the ball with depth and pace in the late going, Williams looked sharper and more comfortable than she did two days ago in the first round, even if she committed too many unforced errors for her taste. But her winners told the analytic tale: three in the first set, 10 in the second, 15 in the third.
Williams will next face 11th seed Julia Goerges of Germany, a player Serena has beaten in both their previous meetings a semi-eternity ago in 2010 and 2011. With no matches on clay until a few days ago, and precious few since she came back in February, she will have to continue to play herself into form.
It's one of the reasons she decided to play doubles with sister Venus, even though it means no off days and that much more challenging of a recovery between matches.
"It's either play doubles or practice for two hours, so I'd rather play doubles," Serena said. "I'm really lacking match play. I'm in a position where I need the matches, and so I'm going to have to play doubles."
She called herself "the world's worst practicer. Everything is wrong. But I'm being nicer to myself. I'm working on that."
Don't expect that gentility to extend across the net, however. When it comes to slamming the door of a match, Williams has had an awful lot of reps.