WIMBLEDON, England — Chasing a drop shot in the second set, Rafael Nadal stumbled and tumbled into the net as his racket went flying to the sideline.
    It just wasn't his day. Nadal rose slowly to cheers from the Wimbledon crowd but found himself off balance the rest of the way and made his earliest Grand Slam exit since 2005.
    Nadal was overpowered in the second round Thursday by Lukas Rosol, a Czech ranked No. 100, 6-7 (9), 6-4, 6-4, 2-6, 6-4.
    The 26-year-old Rosol earned the biggest win of his career playing in Wimbledon's main draw for the first time. He lost each of the past five years in the first round of qualifying.
    As the match stretched beyond dusk, the conclusion came with the retractable roof closed for the final set on Centre Court. The upset on tennis' biggest stage was no fluke: Rosol served brilliantly and repeatedly stepped instead the baseline to hit aggressive groundstrokes, while Nadal found himself pinned deep and on the defensive.
    Among those shocked by the result was Rosol.
    "I'm not just surprised; it's like a miracle for me," he said. "I never expected something like this."
    Nadal saved three set points to win the opening set, but his demeanor grew glum as Rosol overtook him. After falling behind in the third set, Nadal grumbled to the chair umpire during a changeover, apparently irritated by Rosol's movements as he awaited serves.
    "I was concentrating on myself," Rosol said. "I don't know what he was complaining about."
    Two games later, Nadal bumped into Rosol — and didn't acknowledge the contact — as they walked to their chairs for a break.
    Rosol exhaled before hitting his final shot, which was his 22nd ace. He fell to his knees, arms up, then collapsed face down on the famous grass. He then rose and shook hands at the net with a frowning Nadal.
    "I think I was better today a little bit," Rosol said.
    Rosol became the lowest-ranked player to defeat Nadal in a major tournament. The 6-foot-5, 178-pound Czech lost only 16 points on his first serve, cracked his returns into the corners and won 22 of 28 points at the net.
    In short, it was a complete performance that had spectators wondering why they'd never heard of him before. Nadal lost despite committing only 16 unforced errors in 276 points.
    The Spaniard had reached the final in the past five Grand Slam tournaments, and had played in the final of his past five Wimbledons.
    It was a good day for Americans — Serena Williams, Andy Roddick, Mardy Fish and No. 126-ranked Brian Baker advanced, as did No. 28-seeded Christina McHale and Varvara Lepchenko.
    Maria Sharapova's old serving problems resurfaced, costing her the second set before she recovered to beat dangerous Tsvetana Pironkova, 7-6 (3), 6-7 (3), 6-0. The Court 1 match took two days and ended three minutes after Williams concluded her victory on Centre Court, beating qualifier Melinda Czink 6-1, 6-4.
    Defending champion Petra Kvitova, seeded fourth, advanced by beating Elena Baltacha, of Britain, 6-0, 6-4.
    Roddick advanced to the third round at a Grand Slam tournament for the first time in 2012 when he beat Bjorn Phau, 6-3, 7-6 (1), 6-3. Roddick is seeded only 30th and fended off questions in recent months about retirement before he won his fifth grass-court title last week as a wild card at Eastbourne.
    British hopeful Andy Murray faced only one break point and beat big-serving Ivo Karlovic, 7-5, 6-7 (5), 6-2, 7-6 (4). Kei Nishikori became the first Japanese man in 17 years to reach the third round at Wimbledon by beating Florent Serra, 6-3, 7-5, 6-2.
    Sara Errani committed only five unforced errors and beat Anne Keothavong, of Britain, 6-1, 6-1. The 25-year-old Errani, an Italian who has blossomed in Grand Slam competition this year, matched her best Wimbledon showing by advancing to the third round.
    Nadal broke twice in the fourth set to even his match, and gathering darkness made lights necessary for the final set. Tournament officials suspended play for 45 minutes so the roof could be closed.
    Nadal was clearly unhappy that the delay interrupted his momentum, shaking his head and frowning when advised of the situation by an official.
    Serving to start the final set, Nadal shanked a groundstroke on the first point and was broken when he failed to put away an overhead. Rosol easily held from there, winning his final 13 service points, seven with aces.
    Nadal won a record seventh French Open championship this month and was bidding for his third title at Wimbledon, where he was runner-up last year to Novak Djokovic.