Compared with any other tennis stadium roof, only the famous eight petals of the Qi Zhong Stadium in Shanghai come close to aesthetic similarity.

The tin lids at the Caja Mágica in Madrid are incredible feats of engineering but far from easy on the eye and at Melbourne's Rod Laver Arena, where the concept began, two bits of thick metal coming together hardly demand undivided attention.

Yesterday, high above the heads of three grand slam champions and Tim Henman - the so-nearly-but-not-quite man of the British game - the closing of a Wimbledon roof in seven minutes, four seconds drew 15,000 pairs of eyes upwards with the sense of wonder that normally overcomes a first-time visitor to the Sistine Chapel.

Katherine Jenkins, the Welsh soprano and Faryl Smith, a runner-up on Britain's Got Talent, were giving Amazing Grace their all for the official Wimbledon roof inauguration and, as it had been rehearsed, the roof moved with just that.

When the two sides of the structure eventually touched, a spontaneous round of applause burst out. Everything held together perfectly.

The air-management system that has been talked about in relatively hushed tones, did its bit and on walked Andre Agassi, Steffi Graf, Kim Clijsters and Henman. Their reception was so warm that they must have felt the years dropping off them, although in Clijsters's case it does not matter so much because in August she plans to return to the WTA Tour. The Belgian will, with luck, enjoy a similarly warm Centre Court reception again.

For the three elder players, this was an invitation that could not be turned down, even if for the Agassis it meant flying in from Las Vegas, while Henman hot-footed it down the M40 from Oxford. Agassi has always been the showman, his wife less so, but they contrived a real moment of Wimbledon history; the first full-blown kiss on the lips before the first ball of a match was struck.

A mixed doubles match featured the happy couple playing another couple who could not keep smiles from their faces. The first rally was full of clipped volleys and delicate angles and the throwbacks were everywhere. The forehand from Graf had lost little of its precision length and crispness - at one cross-court exchange with Clijsters the boys just stopped and stared. Agassi took a hellish rip at a couple of forehands and bludgeoned one straight into Clijsters's midriff, which temporarily wiped the smile from her face.

Henman, who said he had not been this nervous for a long time, stepped in behind a couple of first serves to plant subtle volleys away. “Old school, Tim,” one man shouted. Wimbledon never minded that.

Agassi defeated Henman in their one-set singles and blew kisses to all corners of the court, as was his wont. Henman punched the air as if he should have won, which was his wont.

But Graf against Clijsters was the high point of the afternoon, for it was clear that the German, who turns 40 next month, had lost none of her court craft.

Clijsters said she could not keep her eyes off Graf's footwork. “She still has those legs,” the Belgian said.

But where did that smile come from? Never had such a contented wife and mother appeared in whites in the famous stadium, which is as beautiful new as it ever was old.

It did not quite match John Trewick's famously dismissive “you've seen one wall, you've seen them all”, when West Bromwich Albion pitched up at the Great Wall of China 30 years ago, but Andy Murray's contribution to proceedings was delivered in a manner both deadpan and impish. “It looks quite nice - compared to most roofs,” said the British No 1, given a cameo walk-on.

The main attraction watched over it all from above - unmoved. It was raining outside but the light shone in. No one fell over. Everyone loved it. Another day when Wimbledon showed the world how it should be done.

Q&A:

Q How high is the roof and what happens if the ball hits it and comes back down on the court?

A The roof is 16 metres high. If the ball hits it then it is deemed that the player who struck the ball has lost the point

Q Who makes the decision to close the roof and what information do they act on?

A Andrew Jarrett, the referee, has the ultimate responsibility. He is in regular contact with the London Met Office. If showers are forecast, the roof can be closed.

Q How long does it take to close?

A The roof itself takes ten minutes to close, with another half an hour for the air-management system to kick in before play can start. Once the roof is closed on a particular match, it will stay closed until its completion.

Q How much did the roof cost?

A Wimbledon are keeping that one to themselves — “we don’t do costings, sorry,” was the answer of Tim Phillips, the chairman of the All England Club, last month. But the general consensus is that the Centre Court renovations have amounted to about £80 million. When the first Centre Court was completed in nine months in 1922, it cost £140,000.

Q How many extra seats are there in the new Centre Court?

A 1,200, which equates to a full house of 15,000.

Q Will there be a need for any further renovations?

A The Club does not think it will need any more improvements for 50 years.