Serena Williams victorious on return to competitive tennis in Miami

Serena Williams is the No. 1 seed in Miami and has won the tournament on five occasions.

Story highlights

  • Serena Williams beats Italian Flavia Pennetta at Sony Open in Miami
  • World No. 1 was playing her first competitive match since mid-February
  • Fourth-seed and defending champion Agnieszka Radwanska into round three
  • China's Li Na of China and Petra Kvitova of Czech Republic also through

Serena Williams shook off any rustiness after a month-long break from competitive tennis as she launched her quest for a sixth Miami title with a straight sets victory over Italian Flavia Pennetta.

The world No. 1 hasn't played since losing to Victoria Azarenka in the final of the Qatar Open on February 17 but made light work of her unseeded opponent winning 6-1 6-1.

Williams, a 15-time grand slam winner, pulled out of the Dubai Tennis Championships after her defeat in Doha complaining of a back injury but looked in good touch as she raced to victory in just under 80 minutes.

"I think I missed a few shots, but only because I think I was off footwork-wise," she told reporters. "But it's always just good just to win a match and stay in the tournament and keep going.

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"I felt like I should be putting the balls away for my opponent but she was so quick and she was running every ball down."

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As for coming into the tournament as the world's best player she said: "It always feels better when you're No. 1. There's nothing like when they announce you and they say, the No. 1 player in the world.

"It definitely gives you a little bit more confidence ... a little more pep in your step. I have a lot of matches to play. If I can just stay relaxed -- I really feel like I can do it, but, you know, I'm sometimes my own worst enemy."

Defending champion and No. 4 seed Agnieszka Radwanska, from Poland, breezed into round three with a 6-3 6-2 victory over Taiwan's Hsieh Su-Wei.

"I was happy to have a quick match," Radwanska was quoted as saying on the WTA Tour's official website. "The first match is always a little bit tough and tricky, especially after Indian Wells, where we had a little bit of different conditions.

"It was a really special tournament for me because I was really playing a lot of good matches against top players and not even losing a set.

"I definitely have great memories from here. And the final was a very good match. Hopefully I can play the same level of tennis this year. I will do everything to hold the trophy again."

China's Li Na, seeded fifth, was also making a return after spending six weeks on the sidelines with an ankle injury but she eased past Dutchwoman Kiki Bertens 6-3 6-1.

"I wasn't nervous before the match today, I was excited," Li told the WTA Tour website. "For the last six or seven weeks I haven't played any tournaments so I was happy to win my first match after such a long time.

"There were a lot of fans there to support me today, I was like, 'Wow!' My game was pretty good today, I followed the plan of what I should do. I just had to believe in myself that I could do it."

Petra Kvitova, the 2011 Wimbledon champion defeated China's Peng Shuai 5-7 6-2 6-2.