Serena becomes oldest No. 1

Doha, Qatar – By virtue of a quarterfinal victory Friday, Serena Williams will reclaim the world No. 1 ranking for the first time in 2 1/2 years and also become the oldest-ever woman to hold down the top spot.

In one of her trademark comebacks, a second-seeded Williams overcame seventh- seeded Czech slugger Petra Kvitova 3-6, 6-3, 7-5 in 2 hours, 7 minutes to reach the semifinals at the $2.369 million Qatar Open. The powerful American swatted 14 aces and tallied four service breaks, compared to three breaks for her left-handed counterpart.

Williams fought back from a 1-4 deficit in the third set and finished off Kvitova with an emphatic match-ending ace.

"I don't know how I did it -- I really don't know," Williams said. "I just hung in there and she was playing so well. Every time I looked around she was hitting a winner. I just tried to stay in there."

The 31-year-old Williams replaces fellow American great Chris Evert as the oldest-ever No. 1. Evert held the spot when she was just shy of her 31st birthday in 1985.

"I'm so sensitive nowadays, I'm always crying!" Williams said as she fought back tears. "I never thought I would be here again. I've just been through so much and never thought I'd be here again."

The reigning Wimbledon and U.S. Open champion Williams will ascend to the top of the rankings when they are released on Monday. Her semifinal opponent on Saturday will be two-time Qatar Open champion Maria Sharapova.

The high-flying Williams has now won 59 of her last 62 matches, which also includes titles at the Olympic Games and WTA Championships. She will begin her 124th non-consecutive week as the No. 1 player in the world next week.

Meanwhile, current world No. 1 Victoria Azarenka and the former top-ranked Sharapova joined Williams in the Doha final four on the hardcourts at Khalifa International Tennis Complex.

The Australian Open champion and reigning Qatar Open titlist Azarenka whipped sixth-seeded French Open runner-up Sara Errani 6-2, 6-2, while a third-seeded Sharapova subdued eighth-seeded former U.S. Open champ Samantha Stosur 6-2, 6-4. Azarenka beat Stosur in last year's Doha finale.

The French Open titlist Sharapova will meet Williams for a 13th time on the WTA circuit on Saturday, with Williams holding a dominant 10-2 lead in their lifetime series. The American has beaten her Russian rival nine straight times, dating back to 2005. Sharapova last beat Williams in the 2004 Wimbledon finale.

One final quarterfinal result saw fourth-seeded Wimbledon runner-up Agnieszka Radwanska dismiss 10th-seeded former world No. 1 Caroline Wozniacki 6-2, 7-5. Wozniacki was the Qatar Open runner-up two years ago.

Azarenka and Radwanska will square off in Saturday's other semi. Azarenka is a dominant 11-3 lifetime against Radwanska, including wins in their last seven meetings. The Belarusian star beat the Polish star in the semifinals here last year.

The 2013 Qatar Open winner will claim $426,000.