Former champion Novak Djokovic lost his opening match at the Sony Ericsson Open to Olivier Rochus 6-2, 6-7 (7), 6-4 on Friday.

Djokovic won the tournament in 2007 and arrived at Key Biscayne with a 15-3 win-loss record this year. But he looked listless at times against Rochus, and by the third set fans were groaning as his errors mounted.

Ranked No. 2, Djokovic drew scattered jeers when he left the court. He responded with a thumbs-up signal.

Djokovic double-faulted 10 times and lost 30 of 44 second-serve points, including 13 of 17 in the final set. He committed 62 unforced errors and converted only three of 13 break-point chances.

Rochus, ranked 59th, improved to 5-8 this year.

“I don’t feel great on the court, and everybody could see that,” Djokovic said. “Life goes on, you know.”

No. 4-seeded Rafael Nadal followed Djokovic into the stadium but not to the sideline, beating American Taylor Dent 6-4, 6-3.

On another dismal day for U.S. men, James Blake and Sam Querrey squandered one-set leads and were eliminated. In women’s play, No. 2-seeded Caroline Wozniacki, No. 14 Kim Clijsters and defending champion Victoria Azarenka advanced to the third round.

Djokovic rarely hit aggressively against the 5-foot-6 Rochus, who lured him into a succession of long, grinding rallies.

“I wasn’t attacking,” Djokovic said. “I was just kind of waiting for him to make the shots, and it wasn’t the right approach. He was making me run a lot, so points were really long. That was exhausting.”

Djokovic was broken three times in the final set, including in the last game.

“I was trying,” Djokovic said. “He was the better player.”

It was the first time since 2002 that 59{+t}{+h}-ranked Rochus has beaten a player ranked so high, and the 29-year—old Belgian said his experience helped in the final set.

“In a match like this before, when I was younger, I would have never won,” he said. “I would have been mentally more negative.”

Wozniacki rallied past qualifier Tsvetana Pironkova 3-6, 6-3, 6-4, and Clijsters beat Petra Kvitova 6-1, 6-1. Azarenka beat Alexandra Dulgheru 6-3, 6-2, finishing shortly before rain began to fall, causing a delay.

There was another delay of 50 minutes later in the afternoon.

In other men’s play, No. 24 Ivo Karlovic hit 28 aces, held every service game and beat Daniel Gimeno-Traver 6-3, 6-7 (5), 6-3. Karlovic had been 0-6 previously at Key Biscayne.

No. 12 Juan Carlos Ferrero and No. 15 David Ferrer also won.

Querrey, seeded 21st, was beaten by Jeremy Chardy 4-6, 6-4, 6-2. Blake lost to No. 27 Thomaz Bellucci 3-6, 6-1, 6-2.

More In: Tennis | Sport