Maria Sharapova battles past Sara Errani to enter Miami Open semis

Maria Sharapova kept her quest for a first Miami title on track on Wednesday with a hard-fought 7-5, 7-5 quarter-final triumph over Italy's Sara Errani.

"With all the tournaments I have played, this one I have been so successful at but yet I haven't won it," said Sharapova, a four-time finalist at the Miami WTA and ATP Masters hardcourt tournament but never the winner.

"I've been so close to winning," she said. "I would love to win this. I've been coming to this tournament since I was a little kid. It would mean a lot to win it."

Sharapova will battle for a place in the final against former world No. 1 Jelena Jankovic, who beat Roberta Vinci 6-4, 6-7, 6-3.

The other women's semi-final was set on Tuesday, with world No. 1 and top seed Serena Williams advancing to take on defending champion and fourth seed Agnieszka Radwanska of Poland.

Sharapova had her struggles against eighth-seeded Errani, the same woman Sharapova beat in last year's French Open final to complete a career Grand Slam.

Sharapova fired six aces, but also had 14 double faults.

Trailing 4-5 in the second, Sharapova saved three set points to knot the set at 5-5. She then broke Errani in the penultimate game and held serve to end it on a forehand winner after two hours and 29 minutes.

Although she was pleased to wrap it up in two sets, Sharapova said she should have sealed it even sooner after twice going up a break in the second set.

"I was up a break," she said. "I had my chances. I was up 30-love on my serve, and those are the type of games that against these types of opponents you need to buckle down and win.

"Of course it's great that I was able to come back, but I felt like I made things much more difficult than they should have been."

Sharapova lost to Kim Clijsters in the 2005 Miami final, to Svetlan Kuznetsova in 2006, Victoria Azarenka in 2011 and Radwanska last year - all in straight sets.

Not only is she trying to fill that gap on her resume, she's trying to become just the third woman to win both the prestigious Indian Wells and Miami hardcourt titles in the same year.

German great Steffi Graf accomplished the feat in 1994 and 1996, and Clijsters did so in 2005.

"I think it's one of the toughest back to backs of the year," Sharapova said. "It's the amount of matches. It's also the late matches that you're playing, the recovery.

"Also coming from different coasts. I mean, it's not just a hop. It's a five-hour flight. Conditions are completely different. It's not easy."