PARIS -- Defending champion and No. 1 Serena Williams was stunned by Spain's Garbine Muguruza 6-2, 6-2 in the second round of the French Open on Wednesday. Muguruza, ranked No. 35, needed only 64 minutes to record her first victory against a top-eight opponent and hand Williams her most lopsided loss at a major.
Williams looked flat and never found her rhythm, finishing with 29 unforced errors and only eight winners while failing to win a point at net (0-for-5). The 17-time Grand Slam champion lost five consecutive games after holding to open the match, and she didn't have a break point in the first set. Williams quickly fell behind two breaks at 3-0 in the second set and missed an opportunity to begin a comeback when she couldn't convert at 0-40 while Muguruza served leading 4-1. Muguruza held at love to close out the biggest win of her young career.
The 32-year-old American, known for her dominance on serve, was broken five times and won only 17-of-31 (55 percent) first-serve points.
"I don't think anything worked for me," said Williams, who was particularly frustrated with her serve. "It was one of those days. You can't be on every day, and, gosh, I hate to be off during a Grand Slam. It happens."
Muguruza, a 20-year-old Venezuelan-born Spaniard appearing in her second French Open, is blessed with easy power and a beautiful forehand and serve. Her game can be volatile, though, with Muguruza sometimes going from good to bad from point to point. But she played lights-out tennis Wednesday.
The up-and-comer dictated most of the points, stayed aggressive and often smacked her groundstrokes down the middle of the court to avoid giving Williams angles -- an approach Muguruza reminded herself to follow while preparing for the match in the locker room. Muguruza hit 12 winners against 18 unforced errors. During their postmatch handshake, Muguruza said Williams told her that if she continues to play this way, she can win the tournament. "I will try, I will try," Muguruza responded.
Said Muguruza: "It's a dream [come true]. Since I was a child, I thought, Oh, I want to play against Serena on center court, and today was the day, and I think I did very good."
In their only other meeting, Williams crushed Muguruza 6-2, 6-0 at the 2013 Australian Open. "I was horrible because I was so nervous," Muguruza said. But since then she has climbed from No. 112 into the top 40. In January, she won the Hobart International as a qualifier for her first title, then reached the fourth round in Melbourne, the final of the Brasil Tennis Cup and the semifinals of the Grand Prix SAR.
"I think now I believe more in me," she said. "I'm more calm, because I know that I can play good."
Still, Muguruza entered the match as a heavy underdog, having gone 0-5 in her career against top-five players and 3-8 against the top 10. In her two most recent tournaments, she had lost to No. 19 Sam Stosur in the second round of the Madrid Open and to No. 61 Francesca Schiavone in the second round of the Italian Open. Williams won the latter event, dropping only one set in five matches.
"I have actually never seen her play like this," Williams said. "Garbine played really well and she played really smart. I didn't adapt."
Williams said the loss would prompt her to "go home and work five times as hard to make sure I never lose again. I know for a fact I can work harder. I know for a fact I can play so much better than what I did today."
Serena also reacted on Twitter:
Congrats 2 my opponent today. She did her thing. I'm proud of her. I wish her well. Until next time. There's always tomm & I will be ready.
— Serena Williams (@serenawilliams) May 28, 2014
Williams has won three titles this year but now has a second-round loss at Roland Garros and a fourth-round loss (to Ana Ivanovic) at the Australian Open. Serena was not kind to herself when asked to review her season through the first two Slams. "I have a couple words to describe it," she said, "but I think that would be really inappropriate so I'm going to leave it at that." Her quest to match Martina Navratilova and Chris Evert for the second-most major titles (18) in the Open era moves to Wimbledon in June.
Earlier Wednesday, Venus Williams lost to No. 56 Anna Schmiedlova 2-6, 6-3, 6-4. The Williams sisters would have met in the third round if both had won. Instead, they both lost on the same day of a Slam for the first time since Wimbledon in 2011.
With Serena's second-round exit and No. 2 Li Na's first-round loss Tuesday, this is the first time that the top two women's seeds were eliminated before the third round of a Slam.
No. 3 Agnieszka Radwanska is the highest seed remaining. The top seed left in Serena's quarter is No. 7 Maria Sharapova.
Here are highlights from Williams-Muguruza:
Here are clips from the postmatch news conferences:
This post has been updated.