Michelle Obama liked what she saw Saturday at Wimbledon. The first lady sat with Williams' family during the 6-3, 6-1 victory over former No. 1 Jelena Jankovic of Serbia.
Williams met with Obama after the match.
"Before, I would have been too nervous," Williams said. "We talked about how I loved her dress. She's always looking good."
Williams looked good, too, picking up where she left off three weeks earlier, when she won her fifth Wimbledon title.
Also happy to be back on grass was Roger Federer, playing for the first time since he won a record-tying seventh Wimbledon title. The top-seeded Federer failed to convert three match points in the second set but recovered from a jittery stretch to beat Alejandro Falla of Colombia 6-3, 5-7, 6-3.
Federer, a fourth-time Olympian, and Williams have yet to win an Olympic singles medal.
While the two Wimbledon champions fared well on the opening day of play, the grass at the All England Club took a troublesome toll. Areas along the baselines reseeded after Wimbledon deteriorated quickly, making the courts slick and causing players to slip and fall.
By the end of the first match on Centre Court, before Williams or Federer stepped onto it, skid marks and barren patches were visible at both ends.
"The grass is a wee bit slippery, but you've just got to deal with it," Williams said. "Get ready to slip and slide, whatever it takes. The area at the net didn't wear out so much. Maybe a lot of the players will start coming to the net."
That would be a change, but then much is different about this particular tournament at Wimbledon. The club was more colorful, thanks to purple backdrops and a waiver of the rule requiring players to wear mostly white. Federer donned a red shirt, Williams went with a blue dress and Falla opted for yellow.
The atmosphere was also more festive, beginning with a morning concert by the Pet Shop Boys on the picnic hill overlooking the grounds. The Centre Court crowd did the wave during changeovers and was more inclined to hoot and holler.
"Wimbledon is so quiet. You know, you don't hear much talking," Williams said. "But here you do hear talking. This atmosphere I didn't expect. It's bananas, and I love it."
Bananas might be a slight exaggeration, but there was a fair buzz with matches on 11 courts.
Four-time Grand Slam champion Kim Clijsters won her Olympic debut by beating Roberta Vinci of Italy 6-1, 6-4. Former Wimbledon champion Petra Kvitova and former No. 1 Ana Ivanovic also advanced.
American John Isner won in his first Olympic match, making the most of a 15-inch height advantage to beat Olivier Rochus of Belgium, 7-6 (1), 6-4. The 6-foot-9 Isner had 24 aces; the 5-6 Rochus had one.
Three other U.S. players lost Olympic debuts — Ryan Harrison, Donald Young and Christina McHale. Isner and Andy Roddick were eliminated in doubles, while top-seeded Bob and Mike Bryan won.
Crowds were smaller than for Wimbledon, with stands on the outer courts less than half full at the start of play. Centre Court was almost at capacity for Williams' match, although four of the six rows in the Royal Box were empty at one point.
To the left sat Obama, who sometimes chatted between points with Williams' sister Venus. Serena had met the first lady before and was advised she would be in attendance.
"They asked me did I mind if she sat in the family box," Williams said. "I was like, 'Of course not. Please, it would be my honour.' I mean, I love Michelle."
As was the case during Wimbledon, Williams won with a dominating serve. She hit eight aces against Jankovic, lost only 10 service points and faced no break points.
The winner of 14 major titles and two gold medals in Olympic doubles, Williams said the incentive to win the singles is different from a Grand Slam event.
"Let's face it, tennis players play to win Wimbledon," she said. "We play to win Australia. We play to win the U.S. Open. The Olympics is a bonus. So sometimes you get the bonus; sometimes you don't."
Federer also tries to downplay his drive to win a singles medal, but there's no question being ousted in the first round while ranked No. 1 would have been a bitter loss.
He was never on the verge of defeat of Falla but twice squandered leads. Federer seemed on his way to a routine win until Falla rallied serving at 3-5, love-40 in the second set.
"He hung tough, and I got nervous," Federer said. "It was a tough set to lose for me, particularly in the situation I was in. That's the beauty of the game. Sometimes you're one point away, and the next thing you know, you're 25 points away."
Federer also blew a 2-love lead in the final set, but had the crowd roaring with a succession of deft shots down the stretch. He's now 264 points from a gold medal.