The £100 million roof was closed with rain falling and a crowd of 15,000 spectators watching Andre Agassi, his wife Steffi Graf, Tim Henman and Kim Clijsters play mixed doubles and singles matches.

The roof was built to limit the frequent rain delays that occur at the Wimbledon Championships each season.

"So often do we just wait around [during rain delays]," said five-time Wimbledon champion Roger Federer in a video message from Madrid, where he beat Rafael Nadal in the final at the Madrid Open.

"For me, it's nice to see that Wimbledon is taking such a big step in the right direction."

Plans for a new roof were unveiled in 2004 and the old roof was demolished in 2007, meaning there was no cover on Centre Court at that year's Championships.

Architectural designers Populous, formerly known as HOK Sport, were also involved with Wembley Stadium and the proposed Olympic Stadium for London 2012.

The roof is made of a lightweight, flexible fabric called Tenara that can fold up on huge trusses.

It takes 10 minutes for the roof to close.