Emma Raducanu says battling through sickness to set up a French Open second-round meeting with defending champion Iga Swiatek is one of the most satisfying performances of her career.

The British number two earned a 7-5 4-6 6-3 victory against China’s Wang Xinyu, despite needing to see the doctor on court towards the end of the first set.

Raducanu, ranked 41st in the world, is making only her second appearance at Roland Garros after missing the past two tournaments with injury.

"I'm actually really proud of today's match, more so than I think a lot of the matches that I played recently or in general, because I woke up and I felt really sick," she said.

"To have come through that and overcome how I was feeling, I'm really happy with it."

The 22-year-old recovered to serve out the opener at the second attempt, but Wang - ranked two places lower - rediscovered her quality to level, partly fuelled by a disputed line-call in the 10th game.

Raducanu, who had her blood pressure taken on court in a lengthy stoppage, then left for a short break before the decider.

The 2021 US Open champion looked invigorated on her return and quickly moved a double break ahead.

The pair continued to trade breaks before Raducanu reasserted her authority - with the 17th break of the match - to secure a gruelling victory in two hours and 44 minutes.

Raducanu's relief at coming through the joint longest clay-court match of her career showed as she wearily dropped her racquet to the ground.

"I was just fighting through. It was really difficult," Raducanu said.

"It didn't really go away throughout the whole match.

"I'm really happy because it would have been easy to let it drag me down."

Victory was yet another example of Raducanu's ever-improving resilience.

Raducanu has previously been accused of not showing enough determination to get through matches when she is not feeling 100% physically.

Before the tournament the former world number 10 also described how she had felt pressured by previous coaches into playing when she knew she was not right.

Raducanu suffered a back spasm in Strasbourg last week, using dry needling and heat therapy to help her recovery.

While this issue was not enough to prevent her facing Wang, it was clear from the start Raducanu had some sort of problem.

At the first changeover she looked anxiously towards her team of Jane O'Donoghue and Tom Welsh, who were providing support with main coach Mark Petchey having work commitments in his other role as a commentator.

After eating a banana to raise her energy, Raducanu still looked a little dazed before eventually asking for the doctor.

However, she dug deep into her limited reserves to win a deciding set for the fourth time this season in eight attempts.

"I have had a lot more three-set matches this year and come out successful more than in the past, which gives me more confidence," Raducanu said.

"I think playing more matches has benefited me in the sense that I'm not out of competition for too long.

"At the same time, when I play matches, I'm really on and really intense, so it does take a lot out of me.

"Finding the perfect balance between being hungry and being ready to play and being fit enough is difficult."

Raducanu can now focus on how to cause a shock against four-time French Open champion Swiatek, who cruised past Slovakia's Rebecca Sramkova 6-3 6-3.

British number one Katie Boulter will aim to join Raducanu in the second round when she plays later on Monday.

Jodie Burrage, playing under a protected injury ranking, lost her opening match.

The 25-year-old was beaten 7-6 (7-1) 6-4 by American former world number seven Danielle Collins.