Former Wimbledon champion Novak Djokovic and this year's Wimbledon runner-up Andy Murray were a pair of easy second-round winners Tuesday at the London Olympics tennis event.

In a matchup of former world No. 1s, a second-seeded Djokovic dismantled previously-hot American Andy Roddick 6-2, 6-1 under the roof on Centre Court at the All England Club, where rain fell on Day 4. The 25-year-old Serbian star fired 13 aces among 33 winners and tallied a mere six unforced errors in advancing.

The reigning Australian and U.S. Open champion Djokovic went 4-for-4 on his break-point chances in the comprehensive victory over Roddick, who had won 12 of his previous 13 matches, including a grass-court title in Eastbourne and a hardcourt victory in Atlanta.

Roddick is a three-time Wimbledon runner-up to the great Roger Federer.

Djokovic was an Olympic bronze medalist in Beijing four years ago.

Meanwhile, the third-seeded British favorite Murray handled Finnish veteran Jarkko Nieminen 6-2, 6-4 on Centre Court. The world No. 4 Murray lost to the Swiss icon Federer in the Wimbledon finale here earlier this month.

Former Australian Open runner-up Marcos Baghdatis upset 16th-seeded Frenchman Richard Gasquet 6-4, 6-4, as the Cypriot Baghdatis will battle Murray in his next outing.

Another second-round result saw 15th-seeded Japanese Kei Nishikori overcome fading former top-five Russian Nikolay Davydenko 4-6, 6-4, 6-1.