Birthday girl Kerber relieved after having to show her mettle
Angelique Kerber revelled as the Rod Laver Arena sang her happy birthday but it was not all smiles for the top seed against Carina Witthoeft in the Australian Open second round.
Kerber, who turned 29 yesterday, was made to dig deep for her 6-2 6-7 (3-7) 6-2 victory over her German compatriot.
There was an angry swish of the racket from Kerber, who for a short period lost focus before finally rediscovering her groove.
She will now play World No.58 Kristyna Pliskova, the twin sister of Karolina, whom Kerber beat in the final here last year.
The World No.1 conducted the crowd, beckoned by on-court interviewer Sam Smith, as they chanted happy birthday after the match.
"I'm feeling like home, so it's great to be in Australia for my birthday," Kerber said. "I just remember that I celebrated my 18th birthday at home, so that was a big party. But the rest, I was always here. It's nice."
Kerber will know she must improve if she is to claim a third Grand Slam after making 34 unforced errors and enduring her second three-set match already in the tournament.
"I was making a lot of mistakes in the important moments," Kerber said. "I was not finding my rhythm from the first ball so I know that I can trust my legs and can run for hours."
Another answering questions about her age is 36-year-old Venus Williams, who is the oldest woman playing singles here.
The American, who made her Australian Open debut in 1998 aged 17, cruised into the second round with a 6-3 6-2 win over Stefanie Voegele of Switzerland.
"I have to talk about this every interview," said Williams, who next plays China's World No.87 Ying-Ying Duan.
"It's an honour and privilege to start that young - and to play this old."
An elbow problem, however, caused her to withdraw from the women's doubles, where she was due to play with sister Serena.