WIMBLEDON, England — Andy Roddick's mood was subdued, his words curt.

WIMBLEDON, England — Andy Roddick's mood was subdued, his words curt.

Once again, he's leaving Wimbledon without the champion's trophy. Only this time, Roddick heads home much earlier than a year ago — and after being beaten by a far-less-accomplished opponent.

The No. 5-seeded American erased an early deficit to even his fourth-round match against 82nd-ranked Yen-hsu Lu of Taiwan, then got broken for the only time all day in the very last game and lost 4-6, 7-6 (3), 7-6 (4), 6-7 (5), 9-7 despite hitting 38 aces Monday.

"It never gets easier," said Roddick, a three-time runner-up at Wimbledon. "Of course I'm going to be (ticked) off when I wake up tomorrow. I mean, if you got fired from your job, you probably wouldn't wake up the next day in a great mood."

The second Monday at Wimbledon is one of the great spectacles in tennis, with all 32 remaining men and women in action, and there was quite an array of stars spread around the grounds. With the temperature moving into the 80s, and a cloudless sky, past Wimbledon champions Federer, Rafael Nadal and the Williams sisters all played — and won in straight sets.

"A wonderful day for the fans," said Federer, who beat No. 16 Jurgen Melzer in the main stadium, then observed, "Obviously I know every corner of this Centre Court. It helps."

Serena Williams followed him out there and pounded 19 aces in her 7-6 (9), 6-4 victory over 2004 champion Maria Sharapova.

In a matchup between former No. 1s and Grand Slam champions from Belgium who recently came out of retirement, No. 8 Kim Clijsters beat No. 17 Justine Henin 2-6, 6-2, 6-3. Henin slid and tumbled to the grass in the match's third game, jarring her right elbow, and wasn't the same the rest of the way.

Lleyton Hewitt, the 2002 winner at the All England Club, lost to 2008 Australian Open champion Novak Djokovic 7-5, 6-4, 3-6, 6-4, while two-time major finalist Andy Murray — Britain's hope for its first homegrown male champion since 1936 — defeated No. 18 Sam Querrey of Santa Monica, Calif., 7-5, 6-3, 6-4 and is the only man yet to drop a set.

Lu's victory over Roddick was Monday's most significant surprise, by far, but it wasn't the only one.

The 62nd-ranked Petra Kvitova knocked off No. 3 Caroline Wozniacki, last year's U.S. Open runner-up, 6-2, 6-0; while No. 82 Tsvetana Pironkova eliminated No. 11 Marion Bartoli, the 2007 Wimbledon runner-up, 6-4, 6-4.

Kvitova and Pironkova each reached her first major quarterfinal. On Tuesday, Pironkova takes on five-time Wimbledon champion Venus Williams, and the 22-year-old Bulgarian is not likely to be too intimidated: She beat the American at the 2006 Australian Open.

The older Williams sister picked up a 6-4, 7-6 (5) victory Monday over 92nd-ranked Jarmila Groth, but this was no easy day of work. Williams showed up late at the office, strolling out at 12:09 p.m. for their scheduled noontime match, saying later she expected to be escorted to remote Court 2.