WIMBLEDON, England -- Former champion Maria Sharapova was knocked out of Wimbledon in a stunning second-round upset Thursday by a 154th-ranked Russian, marking her earliest exit from a Grand Slam tournament since her first full season on tour in 2003.
Her game littered by double faults and ugly unforced errors, the third-seeded Sharapova slumped to a 6-2, 6-4 loss to 20-year-old Alla Kudryavtseva on Court 1.
"She had nothing to lose," Sharapova said. "She went for her shots. I can't be really happy about anything today."
Sharapova, the 2004 Wimbledon champion at age 17, hadn't lost so early in a Grand Slam since going out in the first round at the Australian and French Open and second round at the U.S. Open in 2003.
Sharapova is the second marquee player eliminated in as many days. But her defeat to a little-known player with a career Grand Slam record of 4-5 was a much bigger shock than No. 3-ranked Novak Djokovic's loss to former No. 1 Marat Safin on Wednesday.
Defending champion Venus Williams, meanwhile, overcame another erratic performance and pulled away to beat Britain's Anne Keothavong 7-5, 6-2 and reach the third round, while Jelena Jankovic romped into the
third round with a 6-1, 6-3 win over Spain's Carla Suarez Navarro.
On paper, it seemed inconceivable Kudryavtseva could beat the three-time Grand Slam winner and reigning Australian Open champion -- especially at the tournament where Sharapova made her major breakthrough four years ago.
Kudryavtseva, who was born in Moscow and now lives in Miami, lost in the first round at Wimbledon to eventual champion Venus Williams last year. She has been ranked as high as No. 59 last year.
In their only previous meeting, Sharapova won easily, 6-1, 6-4, at the French Open last year.
But it was clear from the start Thursday that she was off her game -- other than her shrieking grunts, this wasn't the usual Sharapova. She looked listless and finished with 22 unforced errors and eight double faults.
Asked what went wrong, she said, "Not sure. It's a question I'll be asking myself. I think I've got to look at the tape to see what went wrong. It went a little fast to analyze it right now. I felt that I wasn't playing my game. I was letting her take control of the majority of the points."
Sharapova served three double faults in one game and Kudryavtseva took her chances and swept the first set easily in 32 minutes. Kudryavtseva also looked shaky at times in the second set, serving three double faults in the opening game. Sharapova went ahead 2-0, then dropped four straight games.
With Kudryavtseva leading 4-3, Sharapova's second serve on break point was called out, but she challenged the call and the Hawk-Eye replay system showed the ball was in, giving her another chance. When Sharapova served an ace on game point to make it 4-4, she shouted and pumped her fist and seemed to have the momentum.
But Kudryavtseva took the next two games to close out the match. Sharapova double faulted to give her opponent match point, and she converted with a crosscourt forehand winner.
"You can go out there and not feel great and your opponent can make the most of that," Sharapova said.
Earlier Thursday, Venus Williams faced a modest British opponent and was tested to the limit in the first set on Centre Court. The pattern and result were almost identical to her 7-6 (5), 6-1 win against Naomi Cavaday on Tuesday.
The first set alone lasted 1 hour, 9 minutes as Williams struggled to take command against a determined 92nd-ranked player who came into the tournament with only one win at Wimbledon in seven attempts.
"I lost a little bit of focus [in the first set] but got it back, thankfully," Williams said.
Williams jumped to a quick 2-0 lead before lapsing into a flurry of errors that turned the set into a battle of attrition, with the fourth and fifth games taking more than half an hour.
Keothavong held for 2-2 after going to seven deuces, and then Williams saved eight break points in a game that went to 10 deuces, closing it out with a 124 mph service winner.
They went back and forth on serve until Williams broke for the set in the 12th game, hitting a deep backhand return that forced a forehand mistake by Keothavong. Williams broke for 3-1 in the second set with another deep serve return and cruised the rest of the way to close it out in 1 hour, 44 minutes.
There was one tense moment in the second set when, with the two players across the net from each other, Keothavong ripped a backhand that hit Williams full force in the neck area.
"It hurt," Williams said. "This is tennis. You've got to be ready for whatever. I've hit some people, too. That's just how it goes sometimes. I don't think she was aiming for me."
Williams finished with six double faults and 26 unforced errors, 10 more than Keothavong.
"I don't think she liked the way she played," said Williams' mother and coach, Oracene Price. "Well, she wasn't doing the things she should do and knows she should do. It's good it's happening early on. She knows she's going to have to tighten it up."
Williams said she wasn't particularly worried about the state of her game.
"I don't weigh too much into every match," she said. "It's just about getting through to the next round. I'm looking to improve every round, that's not really a huge secret."
Amelie Mauresmo withdrew from the doubles competition after straining her left hip.
She had been scheduled to play doubles with Russia's Svetlana Kuznetsova, who is seeded fourth in the singles.
The women's field already lost one former champion, 1999 winner Lindsay Davenport, when she withdrew with a right knee injury before her second-round match against Argentina's Gisela Dulko, who advanced to the third round by walkover.
The 32-year-old Davenport had limped past Renata Voracova in three sets in her opening match on Tuesday, with her knee heavily wrapped, and decided she wasn't fit to play after practicing Thursday morning.
"It's just really inflamed and painful," she said. "I rested all day yesterday and did treatment. After warming up, I felt like I was 25, maybe 30 percent. That's not good enough for a second-round match."
She had been idle for two months after sitting out the clay-court season and had pulled out of a grass-court warm-up tournament at Eastbourne last week due to the same problem.
Davenport said she expected to be sidelined for up to four weeks, with scans showing she would not require surgery.
Davenport, making her 13th appearance at Wimbledon, beat seven-time champion Steffi Graf in the '99 final and was runner-up in 2004 and '05. She had not lost before the quarterfinals since 1997.