Serena Williams victorious on return to competitive tennis in Miami
updated 5:38 PM EDT, Thu March 21, 2013
Serena Williams is the No. 1 seed in Miami and has won the tournament on five occasions.
- 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
(CNN) -- 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.
Read: Radwanska girls' grand slam ambition
Serena Williams' rise to greatness
Radwanska: Playing Serena was tough
Rafael Nadal returns to the court
Chris Evert: Grooming future champions
"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."
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.
Part of complete coverage on
updated 7:29 AM EDT, Wed May 1, 2013
She towers above him, but she can't do without him. Meet the man who has made Maria Sharapova the world's wealthiest female athlete.
updated 11:11 AM EDT, Mon April 22, 2013
When Maria Sharapova underwent shoulder surgery five years ago, many thought her tennis career wouldn't last.
updated 8:58 AM EDT, Thu April 18, 2013
Nine-year-old Rebecca Suarez stunned onlookers when she was pulled out of the crowd to team up with Del Potro against Nadal.
updated 5:15 PM EDT, Thu April 18, 2013
Janko Tipsarevic is of the belief that his fellow professionals aren't doping -- or at least not on a widespread basis.
updated 10:29 AM EDT, Thu March 21, 2013
Agnieszka and Urszula Radwanska are hoping to take their relationship to a new level by emulating tennis' most famous sisters.
updated 9:24 AM EDT, Tue March 26, 2013
Open Court meets Poland's world No. 4 Agniezska Radwanska, who's making waves on the women's tennis scene.
updated 10:02 AM EDT, Thu March 21, 2013
America's 18-time grand slam champion Chris Evert talks to Open Court about her career and training the next generation of players.
updated 9:44 AM EDT, Thu March 21, 2013
CNN's Don Riddell speaks with 11-time grand slam champion Rafael Nadal during one of his comeback tournaments in Mexico.
updated 10:11 AM EDT, Thu March 21, 2013
Germany's veteran star Tommy Haas opens up to Pat Cash about being away from family on tour, and his many injuries.
updated 7:50 AM EDT, Mon March 11, 2013
You'd think John Isner and Nicolas Mahut would be sick of the sight of each other, but their friendship has grown since that epic match.
updated 11:08 AM EST, Mon March 4, 2013
Almost a decade after Andy Roddick's sole U.S. Open victory, America is still waiting for its next male grand slam winner. What's gone wrong?
updated 11:21 AM EST, Thu February 21, 2013
Open Court's Pat Cash meets American No. 1 John Isner, who experts claim has the potential to win a grand slam.
updated 4:17 AM EST, Mon February 25, 2013
CNN's Pat Cash looks at who the next U.S. grand slam champion might be.
updated 10:45 AM EST, Thu February 21, 2013
CNN's Patrick Snell looks at how the famous couple is helping groom the next generation of tennis stars.
updated 5:09 AM EST, Mon February 25, 2013
With his sights set on the top, Ryan Harrison is the youngest player to win a professional match in 20 years.
updated 11:12 AM EST, Thu February 21, 2013
He's "Mac the Mouth" both on and off the court -- one of the most controversial and iconic players in tennis history, and he's still talking up a storm.
updated 6:31 AM EST, Tue January 29, 2013
Novak Djokovic and Andy Murray have transformed their careers since discovering a diet secret that is battling for mainstream acceptance.
updated 10:00 AM EST, Mon January 28, 2013
Novak Djokovic knew he was going to be a tennis star from an early age when growing up in war-torn Belgrade.
updated 8:25 AM EST, Thu January 17, 2013
Nine women, a bold proposal and a $1 bill. That was what it took for women's tennis to begin a 40-year journey of self-empowerment.