Serena Willliams and Novak Djokovic make it look easy in Australian Open first-round victories

Serena Williams and Novak Djokovic opened their title defenses with straight-set wins at the Australian Open in back-to-back matches on Rod Laver Arena.

The dominant players in tennis entered the season’s first major after contrasting preparations, with Williams coming off a left knee problem that limited her court time and Djokovic warming up with a run to the title at Doha, Qatar.

Williams made a bright start, in a way, holding up one finger and twirling in her neon yellow two-piece outfit to celebrate her 6-4, 7-5 over Camila Giorgi on Monday. Djokovic had a 6-3, 6-2, 6-4 win over Chung Hyeon of South Korea.

Williams and Djokovic each won three of the four major titles last season, with Williams falling two matches short of a calendar-year Grand Slam when she lost in the U.S. Open semifinals. Djokovic’s only loss came in the French Open final.

Williams withdrew from the Hopman Cup because of inflammation in her knee, playing just one set in Perth.

Yet she dropped just one service game against No. 34-ranked Giorgi, who struggled with 12 double-faults, including one on the decisive break point in the 11th game of the second set.

Williams fired two aces and a service winner in the last game.

“I haven’t played a competitive match in a really long time, but I think it was really good for me to come out here,” Williams said. “I was able to stay in it and stay calm today and I think that’s what matters most.”

Williams said she needed the break to recharge at the end of last season and felt OK about her limited preparation.

“I haven’t played in a long time, but I have been playing for 30 years, so it’s kind of — I try to focus on that,” she said.

Two-time Wimbledon champion Petra Kvitova earned the distinction of winning the first completed match at the tournament when she beat Thai qualifier Luksika Kumkhum, atoning for her upset three-set loss in the first round here in 2014.

No. 24 Sloane Stephens of the U.S., who beat Williams in the 2013 Australian Open quarterfinals, lost, 6-3, 6-3, to Chinese qualifier Wang Qiang. No. 26 Anastasia Pavlyuchenkova and No. 27 Anna Karolina Schmiedlova also fell in the first round.

Djokovic’s bid for a sixth Australian Open title started in 93-degree heat, and he was too good for Hyeon, though he was annoyed with himself and his play at times.

Sixth-seeded Tomas Berdych, a semifinalist last year, opened his 50th consecutive major by beating Yuki Bhambri of India, 7-5, 6-1, 6-2, and No. 7 Kei Nishikori had a 6-4, 6-3, 6-3 win over Philipp Kohlschreiber.

Also advancing were No. 12 Marin Cilic, No. 15 David Goffin, No. 19. Dominic Thiem and No. 26 Guillermo Garcia-Lopez. No. 22 Ivo Karlovic was the first of the men’s seeds to exit when he retired due to a left knee injury while trailing Federico Delbonis, 7-6 (4), 6-4, 2-1.