It was blustery, cold, cloudy and drizzly over southwest London -- just the kind of weather fans had prayed for on Sunday when Wimbledon unveiled its new multi-million-dollar retractable roof over Centre Court.

Former Wimbledon champions Andre Agassi and Steffi Graf, along with Kim Clijsters and Tim Henman had been billed to take centre stage for an exhibition event but for once it was not the players who were the main attraction.

At 2.39 pm local time, 15,000 wide-eyed fans tilted their heads back in unison as the 1000-tonne concertina structure over Centre Court started unfurling at eight inches a second.

Seven minutes and four seconds later, the most famous tennis court in the world had become an indoor arena for the first time in its 87-year existence, complete with a translucent roof and bright floodlights.

"It sure has lived up to the beauty that has existed here for a long time. It's an exciting change, it's an addition for the players and the fans," Agassi said before teaming up with wife Graf to take on his European rivals in a game of mixed doubles.

"It's an honour to be part of history here. Any time Wimbledon breaks with its tradition, you have to sign up."

While spectators loudly cheered the moment when the north and south sections of the roof locked together to block out the grey sky and harsh elements, there were some residents who were less than thrilled.

Wimbledon's new innovation had managed to trap two pigeons inside the bowl and they fluttered around in circles desperately trying to find an escape route.

The plight of the birds was the last thing on the mind of the All England Club's chief executive Ian Ritchie, who was using the event as a dress rehearsal for next month's grasscourt Grand Slam.

"Technically the closure worked fine. It was interesting to get the feedback from everybody who played on court because the humidity and the air control were one of the big issues for us. So we will analyse some of the data and see how it all performed and that was the major purpose of today," he said.

Since rain could no longer play spoilsport at Wimbledon, the only fear for the crowd on Sunday was that a worker crawling across the roof, casting a Spiderman shadow as he made a routine repairs, might crash through the fabric.

There was no such drama and Ritchie added that it was important for a traditional tournament like Wimbledon to embrace new technology.

"The two things we are trying to address here is people have a lifetime ambition to get a seat ticket here to Centre Court and I always feel terribly sorry for them when it rains and they miss it," he said.

"Equally, we are in 185 countries around the world on television and people want to see live play. We are [now] able to offer live tennis and that is a huge plus point."

When the venture had been announced five years ago, Henman had been among the sceptics who were concerned that a 'living surface' like grass would get slippery in an enclosed space.

But organisers, who have declined to reveal the exact cost of the project, installed an air management system which removes condensation from within the bowl and stops the grass sweating.

Although the roof has arrived eight years too late for Henman, whose Wimbledon hopes were famously scuppered by rain in 2001 when he was beaten by Goran Ivanisevic in a semi-final that spanned three days, the Briton gave the surface his thumbs up.

"We all know what sort of day it's been outside and it's a real treat to be able to play in the conditions inside when it's so miserable, cold, windy and wet outside," the now-retired 34-year-old said after teaming up with Clijsters to beat Mr and Mrs Agassi in an entertaining contest.

"It feels there is a little humidity in the air ... but in terms of court surface, it's so dry. There is no real effect of there being a roof to the playing conditions. I've only got good things to say about it."

Agassi added: "I was a little worried the conditions, with the roof being closed, would create a level of moisture and make the court more slippery for the players.

"I was really impressed with what I saw, maybe I wasn't running even fast enough to slip, but the movement felt good, the court felt very solid and the sound was magnificent. The way the ball sounds here is going to add to the intensity.

"When you get two people out there who can really play, and move and hit the ball, I think you are going to feel it like a titanic battle that you've not seen yet."

On a day when Wimbledon heralded in a new era, there were some things that remained unchanged.

Before the match, Agassi had quipped: "I was practising really hard for this event. Then they told me I was playing Tim and I stopped." The American beat Henman 6-4.