Roger Federer gave Prince Charles a bow, then gave Fabio Fognini a royal thumping.
With the Prince of Wales visiting Wimbledon for the first time since 1970, Federer was at his best Wednesday and beat Fognini 6-1, 6-3, 6-2.
Federer, a six-time winner at the All England Club, won 37 of 41 points on his first serve and 21 of 23 points at the net against Fognini, an Italian ranked 68th.
Prince Charles and the Duchess of Cornwall sat in the first row of the Royal Box as Federer walked onto Centre Court for the day's first match. He and Fognini stood side by side as they bowed awkwardly toward the royals, and Charles responded with a wave and grin.
"They do brief you beforehand," Federer said. "I guess you don't do anything stupid. You behave. Obviously we were asked to bow, which is obviously no problem to do. We're thrilled for the tennis family that they came to watch Wimbledon today."
Shortly after Federer's victory, rain interrupted play, and the retractable roof on Centre Court was closed for the first time in the tournament. Defending champion Novak Djokovic won under the lights, beating American Ryan Harrison 6-4, 6-4, 6-4 in the final match of the day, which finished at 9:52 p.m.
"We went the distance," Djokovic said. "I'm honored to be in a position to play on the most recognized Centre Court worldwide in our sport. Every time I step on Centre Court, you can feel the different energy from any other tournament."
Former No. 1 Caroline Wozniacki lost under the roof to Tamira Paszek, who saved two match points in the second set and won 5-7, 7-6 (4), 6-4.
Other Grand Slam champions advancing included Kim Clijsters and Andy Roddick, while 2011 U.S. Open champion Samantha Stosur and 2011 French Open champion Li Na lost. More than a dozen matches on outside courts were postponed until Thursday.
Top-ranked Maria Sharapova led 7-6 (3), 3-1 when her second-round match against Tsvetana Pironkova was suspended because of darkness. Sharapova saved five set points in the first set.
When Federer completed his victory, Charles and Camilla joined the crowd's applause. He visited with the royal couple afterward for several minutes, talking about tennis, polo and Federer's young twin daughters.
"They were very nice, very sweet and thought I played great," Federer said, "which was very nice to get some compliments after the match, which was unnecessary, but of course I do appreciate it."
Seeded third, Federer hopes to end his 2½-year drought in major tournaments, and he's off to a good start, losing only nine games through two rounds. He seeks to add to his record total of 16 Grand Slam championships, and he could match the record of seven Wimbledon men's titles set by William Renshaw in the 1880s and tied by Pete Sampras in 2000.
"I'm just happy overall with how I'm playing," Federer said. "I'm serving well when I have to. I'm moving well. I feel like my forehand and backhand are working well. All of a sudden you win quite comfortably, but you have to focus until the very last point, and I'm happy as well with my concentration level."
Sloane Stephens, a 19-year-old American playing at Wimbledon for the first time, saved five set points in the first set and beat No. 23 Petra Cetkovska 7-6 (6), 4-6, 6-3. In the final set, Stephens trailed love-30 in four consecutive service games, yet won them all.
"I'm 19 and I do still have some lapses," she said. "They're less now than I used to have in the past. I really don't get as upset when I lose points now. I'm not that emotional anymore."
Stephens is coming off her first run to the fourth round at a Grand Slam tournament, which happened this month at the French Open.
Heather Watson became the first British woman to reach the third round since 2002 when she defeated American Jamie Hampton 6-1, 6-4.
Sara Errani needed only seven seconds to complete a rain-interrupted win, and she didn't even have to hit a ball.
Errani led American CoCo Vandeweghe 6-1, 5-3 and held the advantage one point from victory when their match was halted Tuesday evening. They returned to Court 16 some 18 hours later, and when Vandeweghe double-faulted into the net on the first point, Errani had the win.
No. 21-seeded Milos Raonic required only one game to complete a rain-interrupted first-round win over Santiago Giraldo, 6-4, 6-4, 6-4. No. 7 David Ferrer reached the second round by beating Dustin Brown 7-6 (5), 6-4, 6-4.
Three-time Wimbledon runner-up Roddick needed three hours over two days to complete a first-round win over British wild card Jamie Baker, 7-6 (1), 6-4, 7-5.
Clijsters, a four-time major champion playing Wimbledon for the final time, advanced to the third round by beating Andrea Hlavackova 6-3, 6-3.
The No. 5-seeded Stosur fell to 6-10 at Wimbledon when she was upset by 72nd-ranked Arantxa Rus 6-2, 0-6, 6-4. Her elimination meant that for the first time since 1939, no Australian man or woman reached the third round at Wimbledon.
Li, seeded 11th, lost to Sorana Cirstea 6-3, 6-4, and No. 13 Dominika Cibulkova was beaten by Klara Zakopalova 6-4, 6-1. Former No. 1 Ana Ivanovic defeated Maria Jose Martinez Sanchez 6-3, 3-6, 6-3.
American Mardy Fish said he declined interviews after his first-round victory because of a stomach problem related to pain medication he's taking for his right arm — and not related to his heart. He expects to be ready for his second-round match Thursday.
Fish spoke to reporters Wednesday, a day after he beat Ruben Ramirez-Hidalgo in straight sets. It was the first match for Fish since a medical procedure in May to try to pinpoint an accelerated heartbeat.