WIMBLEDON, England — Raindrops sprinkled from the sky here at 4:35 p. m. Monday, and rather than a collective moan echoing from Centre Court, there was a thunderous, enthusiastic roar. “Roof! Roof! Roof!” the fans chanted as they closed their umbrellas and pointed their cell phone cameras toward the heavens.

That (and a forecast for more showers) was all the prompting Wimbledon organizers needed to put their $140 million new gadget to use. The translucent retractable roof began to close, and for the first time in the tournament’s 115-year history, grass court tennis was played indoors.

The state-of-the-art roof took eight minutes to close as No. 1 Dinara Safina and former Wimbledon champion Amelie Mauresmo waited for their fourth-round match to resume. Mauresmo led, 6-4, 1-4, when play was halted. There was another 20- minute delay as the air-management system and lights kicked in.

Though the weather cleared up almost immediately, and outer court matches resumed, organizers left the roof closed for the rest of the match, which Safina won, 4-6, 6-3, 6-4.

before been the case at Wimbledon, where unlike at the U. S. Open, for example, there never have been lighted courts, and matches often are stopped in progress because of darkness not much beyond 9 p. m.

Indeed, previously, no Centre Court point ever was played later than 9:35 p. m., and no match on any court at the All England Club ever concluded later than 9:49 p. m.—that record had been set by a 2006 encounter that, coincidentally, Wawrinka lost.

And at a tournament that began in 1877, not a single point had been contested indoors until earlier Monday, when a light sprinkle interrupted No. 1-ranked Dinara Safina’s 4-6, 6-3, 6-4 victory over 2006 champion Amelie Mauresmo. After the fifth game of the second set, the translucent roof above the main stadium was closed, and Safina and Mauresmo finished up underneath — even though by the time they resumed, the rain had stopped.

Because forecasts called for later showers (none arrived), organizers left the contraption sealed for Murray-Wawrinka, which turned out to be a fortuitous decision. All in all, the day’s last match provided far more excitement than the generally open-and- shut cases that dominated the rest of the fourth round.

With all 16 fourth-round matches scheduled, the Williams sisters remained on course to play an all-family final for the second year in a row.

Five-time champion Venus led 6-1, love-1 when Ana Ivanovic retired with a left thigh injury. Two-time champion Serena beat Daniela Hantuchova, 6-3, 6-1. Venus beat Serena in last year’s final.

American 17-year-old Melanie Oudin’s surprising run ended when she lost to No. 11-seeded Agnieszka Radwanska, 6-4, 7-5.

In men’s play, No. 6-seeded Andy Roddick hit 24 aces, never faced a break point and defeated No. 20 Tomas Berdych, 7-6 (4), 6-4, 6-3.

“I’m having so much fun,” said Roddick, a two-time runner-up to Roger Federer. “I love playing here. It really is an honor, and that’s something that is never lost on me.”

Five-time champion Federer hit 23 aces, never lost serve and beat familiar foil Robin Soderling, 6-4, 7-6 (5), 7-6 (5). Federer improved to 11-0 against Soderling, who was broken only once himself, including a victory in the French Open final three weeks ago.

“Today was hard to get through a really dangerous match,” Federer said. “Not many rallies, so maybe not as much fun for the people. But I stayed calm, waited for my chance.”

Roddick’s opponent Wednesday will be 2002 champion Lleyton Hewitt, who rallied from a two-set deficit for the sixth time in his career to beat No. 23 Radek Stepanek, 4-6, 2-6, 6-1, 6-2, 6-2.

No. 22 Ivo Karlovic hit 35 aces and beat No. 7 Fernando Verdasco, 7-6 (5), 6-7 (4), 6-3, 7-6 (9). The 6-foot-10 Karlovic, who has yet to lose his serve in four matches, will face Federer on Wednesday.

No. 4 Novak Djokovic broke seven times and beat Dudi Sela, 6-2, 6-4, 6-1.

In matches today, Radwanska will face Venus, Serena plays No. 8 Victoria Azarenka of Belarus, Elena Dementieva plays unseeded Francesca Schiavone of Italy, and Safina takes on unseeded Sabine Lisicki of Germany.

The men get a day off before their quarterfinals. The other quarterfinals are Murray vs. 2003 French Open champion Juan Carlos Ferrero and Djokovic vs. No. 24 Tommy Haas.