Top-ranked Bob and Mike Bryan were shocked in the first round of the men's doubles on Wednesday, and weren't sure what to do with themselves after their first Grand Slam first-round exit since 2001.

"We're used to at least being in the second week of a Slam," Mike Bryan said after he and his twin fell 6-4, 2-6, 6-2 to unseeded Ivo Karlovic and Frank Moser.

"This is weird. I think it's the first Slam we've been out in the first round in 10 years," he said. "Different, very different."

The Bryan brothers had won three of the last four Grand Slam men's doubles titles and equalled Mark Woodforde and Todd Woodbridge's Open Era record with their 11th Grand Slam title at Wimbledon. However, they could find no answer for the towering Karlovic's booming serve.

"It was a tough matchup, those guys served great and we didn't serve the way we wanted to," Mike Bryan said. "We didn't play our best."