The highest seeded player to fall on Day 1 was No. 6 Tomas Berdych, the 2010 runner-up from the Czech Republic who lost in three straight tiebreakers to 87th-ranked Ernests Gulbis of Latvia. Gulbis, considered a potential top 10 player who never lived up to his potential, served 30 aces to win 7-6 (5) 7-6 (4) 7-6 (4), his first victory at a Grand Slam since the 2011 U.S. Open.
John Isner, the 11th-seded American, was upset in five sets by Alejandro Falla of Colombia, 6-4, 6-7 (7), 3-6, 7-6 (7), 7-5. Isner served 31 aces but was broken to end the contest, a result that ruled out another Wimbledon match between the American and Nicolas Mahut.
Isner beat the Frenchman in the longest match in tennis history here two years ago, an 11-hour, 5-minute marathon that ended 70-68 in the fifth set. Isner beat Mahut again last year in the first round, and the two could have met again this week in round two.
Kim Clijsters, a four-time Grand Slam winner playing in her final Wimbledon, beat former No. 1 Jelena Jankovic of Serbia 6-2, 6-4 in the final match on Court 1. The Belgian, who withdrew from the semifinals of a grass-court tournament in the Netherlands last week with a stomach muscle strain, showed no signs of injury as she extended her career record over Jankovic to 8-1.
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. I'm tough, let me tell you - tough as nails.''
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.