Second-seeded Victoria Azarenka overcame a right knee injury from a scary fall for a 6-1, 6-2 victory over Maria Joao Koehler in her Wimbledon opener.
The second seed in the women's singles, who has been a losing semi-finalist in each of the last two years, was a set and a break ahead of Portugal's Maria Joao Koehler when she fell awkwardly at the back of the court.
It appeared she had suffered a leg injury that might end her involvement in the tournament, but after a long period of treatment the Belarusian ploughed on and clinched a 6-1 6-2 win.
Azarenka hobbled and winced through much of the second set, but Koehler was unable to take advantage of a weakened opponent.
It looked a glum situation for Azarenka when she slipped on the grass by the baseline at 6-1 1-0 in front.
She lay on the court receiving treatment for several minutes before taking an official injury time-out once back in her chair.
After having her right leg massaged and then strapped up, Azarenka put thoughts of abandoning the match out of her mind.
It looked worrying for th 23-year-old Monte Carlo-based player when she immediately served two double faults and had her serve broken to be hauled back to 1-1 in the second set.
But left-hander Koehler often made it too easy for Azarenka, failing to move her around the court as much as she might have.
A third successive break went in Azarenka's favour and from that point she was barely troubled, apart from by the leg problem which was proving more awkward than the player on the opposite side of the court.
Koehler sprayed a forehand wide at 5-2 to present Azarenka with a match point she seized, and Elena Baltacha's conqueror Flavia Pennetta awaits in the second round.
Discussing her injury, Azarenka told the BBC: "I was in such pain at the beginning. I don't know what happened.
"I almost slipped once before that. I'll have to be more careful.
"I'm going to do the best I can just to be ready for the next match. We'll see what happens."
Azarenka explained it was her right knee that was the chief concern.
"It happened so quick in the second that my leg just kind of collapsed," she said. "I felt like my knee just turned to the other way, and it was just so nasty.
"I was in such shock. For two minutes I had such a consistent pain that it just completely freaked me out.
"I didn't think about what was going to happen with the tournament. I just hoped I was okay."
She hopes to be able to carry on in the tournament, but said: "I still have to do some more check-ups to make sure. It's good to have tomorrow to recover. But I still need to make the final assessments.
"I just wanted to give everything I had on that court even though I knew it could get worse. I just wanted to play and try my best.
"At one point I couldn't see the ball. All I could think about is what happened."