KEY BISCAYNE, Fla. (AP)—Roger Federer made a victorious return Friday to the Sony Open after skipping last year's tournament, and then was treated to a tribute on the stadium video screen.

''It looks like a farewell video,'' Federer told the crowd with a giggle. ''I miss one year, and you make me feel guilty.''

Federer is back, as he showed by beating big-serving Ivo Karlovic 6-4, 7-6 (4). Federer lost just three points on his serve to his 6-foot-11 opponent, and in a match with few rallies, he committed only three unforced errors.

Three-time champion Novak Djokovic followed Federer onto the stadium court and into the third round, beating Jeremy Chardy 6-4, 6-3.

Another three-time champ, Venus Williams, defeated Anna Schmiedlova 6-3, 6-3. Williams, the oldest player in the women's draw at 33, is competing at Key Biscayne for the 15th time.

''It's good to be here still as an oldster,'' Williams said.

The 32-year-old Federer has looked rejuvenated recently, and was the runner-up to Djokovic last week at Indian Wells. Federer says his new racket gives him more power, and he is moving as he did in the old days.

After falling out of the top five last year for the first time since 2002, Federer returned to No. 5 this week. He led from the start against Karlovic, making the surprising choice to receive after winning the toss and earning the lone break of the match in the opening game.

''I just felt like, you know, let him go first and see how it goes,'' Federer said. ''It worked well today because I got the early break right away. That relaxed me for the rest of the first set clearly, but still he hung around.''

While Federer had trouble with serves from Karlovic that peaked at 138 mph, the Croat had no chance when returning. Federer won 49 of his 52 service points.

Federer improved to 11-1 in their head-to-head - or, in this case, head-to-shoulder. He said playing Karlovic presents unique challenges that he enjoys.

''Physically it's super easy. There are no long rallies,'' Federer said. ''It's just more like a penalty shootout in soccer.''

The longest point was the last one, and when Karlovic pushed a backhand into the net on the 10th stroke, Federer hopped happily in celebration and threw a fist.

The show of exuberance might be a hint he is keen to do well in a tournament he hasn't won since 2006.

''I'm very relieved and happy to be through,'' he said. It was the first match at Key Biscayne in two years for Federer, who took a spring break in 2013.

Djokovic converted all three of his break-point chances against Chardy, who was hobbled at the end after hurting his right ankle in the next-to-last game.

''When I was supposed to play my best and come up with some good serves and good shots, that's what I did in both sets,'' Djokovic said.

On the women's side, No. 2-seeded Li Na reached the third round when Alisa Kleybanova withdrew because of a viral illness. Kleybanova, who won in doubles on Thursday, is a former top 20-player mounting a career comeback from Hodgkin's lymphoma.

No. 3 Agnieszka Radwanska, the tournament champion in 2012, defeated Romina Oprandi 6-0, 6-4. No. 6 Simona Halep withdrew because of a right toe injury.

Americans Sloane Stephens, Madison Keys and Varvara Lepchenko advanced. Lepchenko outlasted No. 7 Jelena Jankovic 6-3, 2-6, 7-6 (2), and Keys beat No. 31 Daniela Hantuchova 6-4, 6-2.