LONDON — On a chaotic day at Wimbledon when injuries forced seven players to quit, Maria Sharapova managed to play and finish her match.

The end result was the same: Sharapova is out of the tournament.

In the second major Wimbledon upset in three days, the third-seeded Sharapova was knocked out of the grass-court Grand Slam by a 131st-ranked qualifier.

The 2004 Wimbledon champion was stunned 6-3, 6-4 by Michelle Larcher de Brito of Portugal in the second round.

Sharapova slipped and fell several times on the grass on Court 2 and received medical treatment from the trainer in the second set.

It wasn't serious enough to force Sharapova to quit, as so many others did Wednesday either by walkover or mid-match retirements.

Among the casualties: second-seeded Victoria Azarenka (walkover, right knee), men's No. 6 Jo-Wilfried Tsonga (retirement, left knee), John Isner (retirement, left knee) and Steve Darcis (walkover, right shoulder). Darcis was the man who stunned two-time champion Rafael Nadal in the first round Monday.

Also out: 10th-seeded Marin Cilic (walkover, left knee); 2006 quarterfinalist Radek Stepanek (retirement, left hamstring); and Yaroslava Shvedova (walkover, right arm).

The International Tennis Federation said the seven players forced out is believed to be the most in one day at any Grand Slam event in the 45 years of the Open era.

"I would say (it's a) very black day," Cilic said of the spate of injury withdrawals. "The other days, other weeks, there were no pullouts. Everything just happened today."

If that wasn't enough, the tournament lost five former No. 1 players Wednesday: Sharapova, Azarenka, Caroline Wozniacki and Ana Ivanovic among the women, and Lleyton Hewitt among the men.

With Azarenka and Sharapova gone, the prospect of Serena Williams lifting the women's trophy for a sixth time look even stronger. Williams, who is riding a 32-match winning streak, had already been considered the prohibitive title favorite.

There were a few moments of normality on this crazy day at the All England Club.

Second-seeded Andy Murray advanced easily to the third round with a 6-3, 6-3, 7-5 victory over Yen-hsun Lu of Taiwan on Court 1.

Murray served 11 aces and had 41 winners against only 14 unforced errors for his second consecutive straight-set win. The U.S. Open champion remains on course in his bid to become the first British man to win Wimbledon in 77 years.

The 20-year-old Larcher de Brito played the match of her life against Sharapova on Court 2 to reach the third round of a Grand Slam for only the second time.

Larcher de Brito held her nerve in the final 10-minute, 18-point game to serve out the match. She saved two break points and finally converted on her fifth match point when Sharapova hit a forehand into the net.

"I can't believe it," Larcher de Brito said. "I just tried to stay calm. I just played so well. I just hung in there. In the last couple of points or games I just gave it my all and went for it."

Sharapova tumbled several times on the grass. With Sharapova trailing 3-2 in the second set, her right leg gave way behind the baseline and she did the splits.

Sharapova took a medical timeout and complained to the umpire about the grass conditions. She said later she believed she strained a hip muscle.

"I don't think I've ever fallen three times in a match before in my career, so that was a little strange," Sharapova said. "But that's certainly not an excuse.

"I think today I've seen a lot of players fall and take a few hits and a few injuries. So I think that's just part of the game, part of what we have to deal with."

Azarenka, the two-time Australian Open champion, pulled out after hurting her right knee in her opening-round win against Maria Joao Koehler. She withdrew minutes before her second-round match against Flavia Pennetta.

Azarenka reached the semifinals at Wimbledon the last two years and had been seeded to face Williams in the final.

It's only the second time in the Open era that a women's player seeded in the top 2 has conceded a match by walkover at any Grand Slam. The last time it happened was in 1974 at the French Open when second-seeded Nancy Richey pulled out before a match.

In her match against Koehler, Azarenka did the splits near the baseline, then crumpled to the grass, clutching her right knee and sobbing. She recovered after a medical timeout to win.

Azarenka said on Wednesday that medical tests showed she had a bone bruise rather than a tear but was unable to recover in time.

"We tried to do everything we could, but it was a very significant fall," she said. "To recover in two days after that seemed impossible."

Murray's victory came not long after his potential quarterfinal opponent, Tsonga, retired with a left knee injury while trailing Ernests Gulbis 3-6, 6-3, 6-3.

The Frenchman said he had been experiencing a problem with his knee tendon for a few days and it flared up during the match.

"I know when it's going worse and worse like this that it's not really good for me to play on because I know I will do more damage," he said.

Darcis withdrew a few hours before his scheduled match against Lukasz Kubot of Poland. He said he hurt his right shoulder while diving for a shot in the first set of his win against Nadal.

"After the match, a few hours after, I start to feel so much pain, I couldn't sleep that night," he said. "I saw the physio, the doctor, yesterday. They did a good job. It's a little bit better today. But no chance I can play."

Darcis had become an overnight sensation after beating the eight-time French Open champion.

"I was playing maybe the best tennis in my life here," Darcis said. "Not to go on the court today, it's maybe the biggest disappointing thing I have to do."

The tournament also lost 2002 champion Hewitt, who was ousted by 189th-ranked German qualifier Dustin Brown, 6-4, 6-4, 6-7 (3), 6-2.

The dreadlocked Brown, who switched nationality from Jamaica in 2010, was in tears after beating the Australian.

"I cried like a little girl," said Brown, who has played mainly on the lower-tier challenger circuit in 2013 and had never won a match at Wimbledon until this year.

Ninth-seeded Wozniacki slumped to a 6-2, 6-2 loss to 196th-ranked Czech qualifier Petra Cetkovska, continuing her disappointing run since finishing 2011 as No. 1.

The Dane said she slipped during the match and her foot was bothering her.

"I didn't feel 100 percent out there after I slipped," she said. "I overstretched the foot a bit."

In another women's match, Canadian teenager Eugenie Bouchard picked up the biggest victory of her career, beating 12th-seeded Ana Ivanovic, the 2008 French Open champion, 6-3, 6-3 to reach the third round.

Isner, the 18th-seeded American, retired during his second-round match against Adrian Mannarino of France after only two games.

Isner took a medical time out during the second game and a trainer taped the knee. But he was clearly hobbled and decided to quit after serving the first point in the third game.

The retirement came three years after Isner beat Nicolas Mahut 70-68 in the fifth set at Wimbledon in the longest match in tennis history. Now, Isner is out after one of the shortest matches at Wimbledon.

Isner said he felt something in his knee when he landed on his left leg after hitting a serve on the third point of the match.

"I always serve and land on my left leg, like I have done 20 million times playing this game, and this is the first time I just felt this sharp pain," he said. "It didn't pop. It just grabbed like really badly, and I knew I was in serious trouble then. I knew at that point it was not likely I was going to be able to play."

Isner said it appeared to be a tendon injury, not a major tear, and he does not expect to need surgery.

"I just can't bend my knee," he said. "I can walk as long as I keep it straight."