Novak Djokovic helped dry Wimbledon's Centre Court with his towel on Monday, appealing to fans to "blow" on the court during a lengthy delay.

The roof was closed just after the Serbian seven-time champion wrapped up the first set 6-3 against Argentina's Pedro Cachin, with rain falling in southwest London on the opening day of the championships.

The covers came on quickly but the officials and players studied the surface of the lush grass carefully, apparently concerned over damp patches.

One member of the groundstaff swept the surface before three men emerged with hand-held driers, to cheers from the crowd.

Djokovic, who rubbed the court with his white towel, joked with the crowd: "Blow, we need your help."

One spectator shouted: "Get on with it".

The clock ticked past one hour since the last point had been played as efforts to dry the court continued.

"Match suspended -- slippery surface," a TV caption said.

Djokovic is bidding for a record-equalling eighth Wimbledon crown and a 24th Grand Slam singles title.

jw/dj