Former world number one Wozniacki burst out of the blocks as she claimed the dominating 6-0 first set victory.

But then it all began to unravel as Russian challenge Veronika Kudermetova swung the momentum in her favour.

Kudermetova, 22, took control of the game and proved too strong for the 13th seeded Wozniacki to handle as she claimed the 0-6, 6-3, 6-3 victory to move into the second round.

Wozniacki’s record this year dropped to 9-8 after her fourth straight loss — including first-round defeats in Madrid and Rome — since reaching the final of a clay-court event in Charleston, South Carolina, last month.

The 13th-ranked Wozniacki announced in October that she has rheumatoid arthritis.

The match marked Kudermetova’s debut in the main draw at Roland Garros and the biggest win of her career in terms of ranking. The Russian player hit a whopping 40 winners to Wozniacki’s 15.

FORMER SLAM CHAMP OUT

The French Open women’s draw has been busted wide open with major news landing ahead of the day two action.

Two-time Wimbledon champion Petra Kvitova said she expects to be fit for the grass-court season despite pulling out of the French Open with a left arm injury on Monday.

The Czech, who was seeded sixth at Roland Garros, will be out for “two to three weeks”.

“It means no tennis, of course, as it’s my left forearm,” said the big-hitting left-hander.

“Maybe I can play rightie. Two to three weeks, so I’ll do some fitness and everything that I can do to prepare my body for the tennis on the grass.”

Kvitova had been due to play Romania’s Sorana Cirstea in her opening Roland Garros match on Court Suzanne Lenglen later in the day.

“I am so disappointed to have to announce my withdrawal from Roland Garros,” Kvitova wrote on Twitter.

“I have had pain in my left forearm for a few weeks and last night an MRI confirmed a Grade Two tear which unfortunately could get worse if I play today.”

The 29-year-old made her return from a horrific hand injury, sustained in a knife attack by an intruder at her home, at Roland Garros in 2017.

“Two years ago I made my comeback here at Roland Garros, so I’m truly sorry not to be able to play this year,” she added.

Kvitova has been replaced in the draw by 18-year-old Slovenian lucky loser Kaja Juvan.

DEMON MAKING IT LOOK EASY

Aussie Alex de Minaur put on a show on the outside courts as he took on American Bradley Klahn.

Seeded 21st in the tournament, de Minaur quickly took care of business as he ran away with the 6-1, 6-4, 6-4 victory in a little over an hour.

An opening round win sets up a showdown with Spanish player Pablo Carreno Busta who comfortably claimed the 6-3, 6-1, 6-2 victory.

Day two will see plenty of Aussies hit the clay with Sam Stosur, Ash Barty and Astra Sharma all in action.