Australian Open: Serena, Kvitova, Djokovic, Berdych and Radwanska go through; Errani falls through

Defending women's champion Serena Williams reached the second round of the Australian Open with a tense 6-4 7-5 win over Italian Camila Giorgi in her first tour match in four months.

The American, 34, had been struggling with a left knee injury in the build-up, but came through unscathed.
Men's champion Novak Djokovic eased through in straight sets, beating South Korea's Hyeon Chung 6-3 6-2 6-4.
Roger Federer and Maria Sharapova are also in action in Melbourne on Monday.
Players struggled as temperatures reached 33C but the main talking point was a report which said 16 top-50 players over the past decade, including Grand Slam doubles champions, had repeatedly been suspected of match-fixing without facing action.

Sixth seed Petra Kvitova was the first player to win a match, beating Thailand's Luksika Kumkhum 6-3 6-1.

The two-time Wimbledon champion, who lost to the Thai in the first round in 2014, was playing her first match of the year after a stomach virus forced her to pull out of two warm-up events.
"Now I can breathe a little bit normally," said the Czech. "I got really nervous before the match. I didn't sleep well actually. The memories from two years ago were a little bit difficult.
"I had an interrupted lead-up and lost some weight but I'm feeling much better now."

Czech sixth seed Tomas Berdych and Japan's seventh seed Kei Nishikori both breezed into the second round with straight-set wins.
Fourth seed Agnieszka Radwanska of Poland beat Christina McHale 6-2 6-3.

Czech sixth seed Tomas Berdych and Japan's seventh seed Kei Nishikori both breezed into the second round with straight-set wins.
Fourth seed Agnieszka Radwanska of Poland beat Christina McHale 6-2 6-3.
 
Italy's Sara Errani, the 17th seed, had injury problems and became the first women's seed knocked out, losing 1-6 7-5 6-1 to 21-year-old Russian Margarita Gasparyan.
The 24th seed, Sloane Stephens, who beat Serena Williams in the 2013 Australian Open quarter-finals, went out 6-3 6-3 to Chinese qualifier Wang Qiang.
Big-serving Croatian Ivo Karlovic became the first player to retire on court during the tournament, pulling out of his contest with Federico Delbonis on Court 14 in the third setwhile trailing 7-6 (7-4) 6-4 2-1.

 (c) BBC.com