WIMBLEDON, England -- Racket bag slung over her shoulder, resignation written across her face, Venus Williams weaved through fans milling about on the sidewalks that players must traverse to get from Court 2 to the Wimbledon locker rooms.
The 32-year-old Williams had just absorbed a lopsided first-round loss at the Grand Slam tournament she once ruled, a poor performance that raised questions about how much longer she will keep playing tennis while dealing with an energy-sapping illness.
She trudged by as her hitting partner, David Witt, was saying: "It's tough to watch sometimes. I think everybody sees it. I don't know what else to say."
Looking lethargic, and rarely showing off the power-based game that carried her to five Wimbledon titles and seven majors overall, Williams departed meekly Monday with a 6-1, 6-3 defeat against 79th-ranked Elena Vesnina of Russia. Only once before -- as a teenager making her Wimbledon debut in 1997 -- had Williams exited so early at the All-England Club.
She hadn't lost in the first round at any Grand Slam tournament in 6½ years. Still, Williams said she'll be at the London Olympics next month and is "planning" to be back at Wimbledon next year.
"I feel like I'm a great player," Williams said, sounding a tad like someone trying to convince herself.
She repeated that affirmation as she continued: "I am a great player. Unfortunately, I had to deal with circumstances that people don't normally have to deal with in this sport. But I can't be discouraged by that. ... There's no way I'm just going to sit down and give up just because I have a hard time the first five or six freakin' tournaments back."
Later, as part of a slightly testy and awkward exchange with reporters, Williams said: "I'm tough, let me tell you. Tough as nails."
There were no opening-day troubles for top-ranked Maria Sharapova, who enjoyed an easy straight-set win on a cloudy but dry start to the two-week grass court championships.
Sharapova, who won the French Open this month to complete a career Grand Slam, picked up right where she left off at Roland Garros. She thoroughly dominated the 133rd-ranked Anastasia Rodionova, a Russian-born Australian, to win in just over an hour.
Sloane Stephens, a 19-year-old former junior doubles champion at Wimbledon, was the first American woman to win a match, 6-2, 6-2 over Karolina Pliskova. Stephens will face Cetkovska in the next round.
Americans fared better later in the day. Jamie Lee Hampton upset No. 27 Daniela Hantuchova 6-4, 7-6 (7-1), and 28th-seeded Christina McHale was even with Australian Johanna Konta 7-7 in the third set when play was suspended because of darkness.
Hampton had never played a match on grass before, and she first practiced on grass when she got to London. She wasn't sure whether she'd be able to enter the Grand Slam tournament after she quit during her opening match at the French Open last month because of two herniated disks.
"In the back of my mind I'm sure I was worried about whether my back was going to hold up or not," Hampton said after the match. "It's a little stiff but it's all right. It sounds worse than it is."
The 32-year-old Williams, playing in her 16th straight Wimbledon, was unseeded for the first time since 1997. She was coming off a second-round loss at the French Open to Agnieszka Radwanska.
Williams revealed in late August at the U.S. Open that she had been diagnosed with Sjogren's syndrome, an autoimmune condition that can cause fatigue and joint pain. She skipped the Australian Open in January, before returning to the tour in March in a bid to earn a berth on the U.S Olympic team for the London Games.
"I've been through a lot for years without knowing what I was going through," she said. "It's all a culmination at the end of the day. I just try to stay positive and focus on the tennis."
Williams has been champion or runner-up at the All England Club eight of the past 12 years, with her last title coming in 2008. The three losses in finals all came against younger sister Serena.
"I don't have time to feel sorry for myself," she said. "I'm not going to give up on it. ... There's no way I'm going to just sit down and give up just because I have a hard time the first five or six tournaments back. That's just not me."
The Olympic tournament will be played at Wimbledon three weeks after the end of the championships.
"At the Olympics, you'll see me here," she said. "I'm planning on it."
The 25-year-old Vesnina, who reached the fourth round here in 2009, played smart and steady baseline tennis to keep Williams at bay. It took 30 minutes before Williams won a game. But Vesnina broke right back to close out the set with a forehand winner.
The second set was much more contested, but once the Russian broke again for a 4-2 lead, she was in full control. Three games later, Vesnina cracked a big first serve on match point and Williams slapped a forehand return into the net.
Play began right on time at 11:30 a.m. on the outside courts under cloudy skies but without any threat of the rain that has soaked London and parts of Britain for much of the past few weeks. Temperatures reached 72 degrees.
Clijsters is playing at the All England Club for just the second time in six years and has said she is retiring after this year's U.S. Open -- this time for good, having returned to the sport in 2009 after a two-year break.
The 47th-ranked Belgian looked to have recovered fully from recent injuries, breaking the 18th-seeded Jankovic five times -- including at love in the final game to clinch the victory.
She improved her record to 8-1 against Jankovic.
Radwanska, who has twice reached the quarterfinals at Wimbledon, beat Magdalena Rybarikova of Slovakia 6-3, 6-3 in the day's first match on Court 2.
Rybarikova took an injury timeout after her left leg gave way, which caused her to fall behind the baseline while trailing 2-1 in the second set. After treatment, she returned to the match with her leg heavily wrapped and did not seem bothered by it the rest of the way.
The fifth-seeded Stosur, the 2011 U.S. Open champion, cruised to a 6-1, 6-3 win over Carla Suarez-Navarro of Spain. The hard-hitting Australian has traditionally struggled on the grass at Wimbledon, losing in the first round the past two years and never advancing past the third, but she was always in command Monday.
Li, the 2011 French Open champion who is seeded No. 11, swept past Ksenia Pervak of Russia 6-3, 6-1.
Information from The Associated Press was used in this report.