MELBOURNE, Australia: Angelique Kerber smiled and waved her arms like an orchestra conductor as the Rod Laver Arena crowd sang "Happy Birthday" after her 6-2, 6-7 (3), 6-2 second-round win on Wednesday at the Australian Open.

The defending champion wasn't completely on song on her 29th birthday, angrily swiping her racket in the second set in a burst of frustration that momentarily threw her off her game ? and allowed Carina Witthoeft back into the match.

Top-ranked Kerber was cool and controlled in the first set, but struggled against some deep, powerful forehands late in the second.

In the tiebreaker, she led 3-2 but double-faulted twice ? once on either side of the change of ends ? as Witthoeft won five straight points to level the match.

The tension mounted when she dropped her serve to open the third set, but Kerber recovered her composure and took a 4-1 lead, saving two break points in the fifth game.

After skewing a forehand wide on match point, Witthoeft went to the net and gave her fellow German a kiss on each cheek. Kerber can celebrate, then get back to work on Friday against Kristyna Pliskova, who beat No. 27 Irina-Camelia Begu 6-4, 7-6 (8). Pliskova's twin sister, Karolina, lost the U.S. Open final to Kerber.

"I'm always playing on my birthday ? always in Australia," said Kerber, who had her major breakthrough here last year by beating Serena Williams in the final. She later won the U.S. Open and replaced Williams as the year-end No. 1. "I feel like at home here. I'm 29. I'm getting older, but I think I'll have a great day today."

Speaking of age, Venus Williams had to field questions about getting older after energetic performance in her 6-3, 6-2 second-round win over Stefanie Voegele.

The 36-year-old, seven-time singles major winner played the first of her record 73 Grand Slam tournaments at the French Open in 1997. Back then, she got to play against the likes of Steffi Graf and Martina Navratilova.

"I have to talk about this every interview!" Williams said. "I've played some of the greats."

"It's an honor and privilege to start that young," she added, laughing, "and play this old."

Venus and Serena Williams withdrew from a scheduled first-round doubles match later Wednesday, citing an injury to Venus' right elbow. The sisters have won 14 Grand Slam doubles titles together, including four at the Australian Open.

Venus thought she could manage the injury and play both singles and doubles, but decided she couldn't after her singles match went 83 minutes.

In the second set, serving and with a game point, she chased the ball like a teenager from one side of the court to the other, and back, trying to finish off. Her forehand landed too long, but her intention was clear. Get through the round ASAP.

At 15-15 and 5-2 in the second, she was still remonstrating with herself after missing a point. She finished off the match later in the same game, another break, to reach the third round. Williams lost to eventual semifinalist Johanna Konta in the opening round last year.

In the next round she'll play Duan Yingying, who beat Varvara Lepchenko 6-1, 3-6, 10-8. Two-time major winner Svetlana Kuznetsova beat Australian wild-card entry Jaimee Fourlis 6-2, 6-1 and will next play former No. 1-ranked Jelena Jankovic, a 6-3, 6-4 winner of Julia Goerges.

Alison Riske defeated No. 20 Zhang Shuai 7-6 (7), 4-6, 6-1.

No. 11 Elina Svitolina had a 6-4, 6-1 win over U.S. qualifier Julia Boserup to advance to a third-round match against

No. 24 Anastasia Pavlyuchenkova, a 6-2, 6-2 winner over fellow Russian Natalia Vikhlyantseva .
On the men's side, No. 10 Tomas Berdych had a 6-3, 7-6 (6), 6-2 win over Ryan Harrison and could meet 17-time

Grand Slam winner Roger Federer in the next stage. U.S. Open champion Stan Wawrinka advanced 6-3, 6-4, 6-4 over Steve Johnson.

Fifth-ranked Kei Nishikori set up a third-round match against Lukas Lacko with a 6-3, 6-4, 6-3 win over Jeremy Chardy, and No. 12 Jo-Wilfried Tsonga beat Dusan Lajovic 6-2, 6-2, 6-3. -AP