NEW YORK, USA (AP) — Roger Federer provided a tennis clinic both during and after his win over Dudi Sela at the US Open yesterday.

Prompted in the on-court interview after his 6-3, 6-2, 6-2 victory over the Israeli to give all the tennis players in the stands a few quick pointers about how to dial in their serve, Federer offered this advice.

“It all starts with a good ball toss,” he said after moving easily to the third round. “Sometime, people think it’s just the swing, but I think the ball toss creates your motion after that. You should keep your elbow high on the serve, then the better you get, the more you can use rotation and legs.”

It worked great against Sela. Federer finished with six aces and maxed out at 128 mph in what looked very much like a tuneup — a second-round win that took only 1 hour, 17 minutes.

Federer came into the US Open as the third seed and is trying to avoid going an entire year without a major victory for the first time since 2002. He turned 30 on August 8, prompting questions on how long he can play at an elite level.

Against the 93rd-ranked Sela, though, none of this was an issue. Federer improved to 58-6 for his career at the US Open.

After the Federer match, No 28 Serena Williams took the court at Arthur Ashe Stadium and had an equally easy time. She beat Michaella Krajicek, 6-0, 6-1, in 49 minutes to end the day session about three hours earlier than normal.

The other day match in Ashe was No 7 Francesca Schiavone’s 6-1, 6-1 victory over Mirjana Lucic.

Williams, who pulled out of a tuneup match in Cincinnati last month, hasn’t lost a match in which she’s actually taken the court since the round of 16 at Wimbledon.

No 1 Novak Djokovic and No 8 Mardy Fish were scheduled for later matches, as was top-seeded woman Caroline Wozniacki, in search of her first major title.

In other early action, No 16 Ana Ivanovic got a walkover when Petra Cetkovska pulled out with an injured quadriceps.

No 11 Jelena Jankovic and No 18 Roberta Vinci also advanced in straight sets while No 10 Andrea Petkovic needed three sets to get by Zheng Jie of China.

On the men’s side, ninth-seeded Tomas Berdych defeated Fabio Fognini of Italy, 7-5, 6-0, 6-0, while No 7 Gael Monfils took a 2-1 sets lead over Spain’s Juan Carlos Ferrero.

Meanwhile, Juan Carlos Ferrero outlasted seventh-seeded Gael Monfils, 7-6 (5), 5-7, 6-7 (5), 6-4, 6-4 in a thrill-a-minute match that lasted nearly five hours to reach the third round.

The crowd in Louis Armstrong Stadium saluted both players with a standing ovation before the final game, which the 31-year-old Ferrero served out at love.