Serena Williams survived a scare as she fought back to beat Russian world number 83 Vitalia Diatchenko in the French Open first round.
American Williams, who has been battling injury, showed rustiness in a poor first set filled with loose shots.
But the 23-time Grand Slam champion found her rhythm to claim 12 of the final 13 games and win 2-6 6-1 6-0 at Roland Garros in Paris.
Williams, 37, faces Japan's Kurumi Nara or Slovenian Dalila Jakupovic next.
"There is always a lot of fear for a first-round match," Williams said.
"I made lots of mistakes in the first set and I just said 'good luck, Serena'.
"I was strong after that. Now I feel like I need to go and practise."
From screams of frustration to a milestone
The women's draw at Roland Garros had already lost Wimbledon champion Angelique Kerber and former world number ones Caroline Wozniacki and Venus Williams to first-round defeats, while sixth seed Petra Kvitova pulled out injured.
It started to look like Williams' name would be added to the list of casualties.
Her season has been disrupted by a persistent knee injury and she was even pictured sat in a wheelchair - seemingly as a protective measure - on a trip to Disneyland Paris with her daughter Olympia last week.
The injury forced her to pull out of the Italian Open two weeks ago, meaning she had played only once on clay since last year's Roland Garros.
Since losing to Karolina Pliskova in the Australian Open quarter-finals in January, Williams has played in only three tournaments - Indian Wells, Miami and Rome - and has withdrawn from all of them.
So it was unsurprising to see the 10th seed make 14 unforced errors in the opening set against 28-year-old Diatchenko.
Loud screams of frustration at the start of the second set seemed to have a cathartic effect, with Williams finding her stride soon after.
The three-time French Open champion, who is aiming to equal Margaret Court's record of 24 Grand Slam singles titles, hit 20 winners in the final two sets as she increased the intensity against a rapidly wilting Diatchenko.
In the end it was a procession to an 800th victory in the main draw of a tournament as Williams became the first woman to reach the milestone.
The catsuit was banned - so what did she wear?
Williams was banned from wearing the black catsuit outfit she donned at last year's French Open, with the tournament introducing a stricter dress code.
She said the outfit made her feel like a "superhero" and that it helped with the issue of blood clots, which she said almost cost her her life giving birth.
She answered the 'what will she wear?' question when she arrived on Philippe Chatrier wearing a black and white striped cape emblazoned with the words 'mother, champion, queen, goddess'.
"It was just to remind everyone that they can be champions and are queens. So I love that about it," she said.
"It is a lot to carry, but so is being Serena Williams."
That was just for the warm-up, after which she revealed an abstract outfit in the same colours, which looked like floating shorts and a crop top but which also had a mesh panel around the torso.
Even then she was not finished with the outfit changes, later pulling on a - remarkably plain - long-sleeved top.