SERENA Williams admits only brutal determination allowed her to escape Ash Barty’s French Open clutches as the Australian rued a lost opportunity.

Under siege when trailing by a set and a service break, Williams ruthlessly turned back the clock to deny Barty 3-6 6-3 6-4.

In her best performance since winning the Australian Open last year, Williams responded to Barty’s inventive genius the only way she knows how.

I have definitely always had that will to win. It was something I was born with, thank goodness,” she said.

“This is a grand slam. This is my first one back. I want to do the best that I can.

“I want to be able to, you know, just do my best and one day tell my daughter that I tried my best.

“When I was out there, that’s all I was just trying to do, is just do that.”

Contesting her first grand slam since having a daughter in September, Williams bludgeoned the silken Australian into the red dust just as Barty threatened bury Williams.

In a high quality clash, Williams blasted 28 winners and nine aces to Barty’s 17 and three.

She high-stepped in delight after driving a backhand winner down the line before warmly complimenting Barty as the pair shook hands at the net.

Barty was shattered as she walked off Court Philippe Chatrier - but need not have been.

“I think when push came to shove, the real Serena came out,” Barty said.

“And that’s one of her best assets is when her back is against the wall, the best comes out. And that happened early in the second, and early in the third again.

“I think any time you get to play a champion like Serena, it’s amazing. And, I mean, I played well.

“I feel like I wasn’t really too much wrong. Like I said.. give me half a dozen forehands and ten more first serves and maybe it’s a different outcome.

“This clay court season, we’ve played well and gone unrewarded a little bit. Played some good players.

“But at the end of the day, I gave it a crack and it wasn’t enough.”

Barty was brilliant in the first set and conjured another service break in the opening game of the second bracket.

From there, having stirred Williams into action, she fought doggedly to stay on terms.

But nothing, not even inspired Barty, was going to stop the 23-time major winner.

When Williams and Barty met for the first time at the 2014 Australian Open, Williams was No 1 in the world and in the midst of 22-match winning streak.

At the time, Barty was 17 and ranked 155th in the world. Predictably, Williams won the match, 6-2 6-1.

So much has changed over the intervening four years.

Barty, 22, has risen to No 17, having returned to the sport after a brief - and successful - dalliance with cricket as a salve to burn-out.

The junior Wimbledon champion is now a bona fide star of the women’s game, renowned for precision as much as the cerebral style she uses.

Williams, 36, remains a titan of the sport despite playing only two majors in the past 15 months.

She is not yet physically anywhere near her peak though and it showed against the heady Barty during the first set.

But her sheer will power remains. And so does her phenomenal power.

Combined, they threaten to carry her deep into this tournament.

Chasing a fourth French title, an achievement which would allow the right-hander to draw level with Margaret Court’s record tally of 24 singles majors, Williams next plays Julia Goerges.

The German downed Belgian Alison van Uytvanck 7-5 7-6 (7-5).