While fellow thirty-year-old and American Andy Roddick was announcing his retirement, Serena Williams took to the court to dispatch Maria Jose Martinez Sanchez in straight sets to advance to the third round of the U.S. Open.

Williams wasn't at her best during the match, but was able to defeat her opponent easily, winning the first set in only 34 minutes and taking the match 6-2, 6-4.

The fourth-seeded Williams outmatched Sanchez in winners 32-5, but had 24 unforced errors and six double-faults. She had 11 aces in the match and frequently hit over 100 mph on her serves.

"I wasn't really happy with the way I was playing," Williams said, according to the Associated Press. "I just wasn't happy out there today in general. I think I woke up on the wrong side of the bed."

Prior to the U.S. Open, Williams had been using her serve to dominate opponents, including at the Olympics, where she won a gold medal for the United States and at Wimbledon in July.

The American star has had a controversial past with Sanchez, stemming from an incident at the French Open three years ago. Williams thought a ball she hit had grazed Sanchez's arm and should have been awarded the point. She felt her opponent cheated by not admitting to the error.

The three-time U.S. Open champion will turn 31 on Sept. 26, but has no plans of retiring like fellow players Kim Clijsters and Andy Roddick.

"It makes me want to stay more," Williams said to the Associated Press. "Losing Kim was so hard. I saw her yesterday. I just hugged her. My eyes got watery. ... I didn't expect that reaction."

Williams will face Ekaterina Marakova of Russia in the next round. Marakova, who is ranked 42nd, previously knocked Williams out of the Australian Open earlier this year.