(CNN) -- Serena Williams is through to her ninth Miami Masters final after beating Maria Sharapova at Crandon Park on Thursday.
Defending champion Williams trailed early on in the match before powering her way past her Russian opponent in straight sets 6-4 6-3.
Sharapova had worked an early lead, breaking in the fourth game of the opening set and led 4-1 at one stage.
But her advantage was short-lived as Williams reeled off five games in a row to close out the set.
The fourth seed broke Williams again in the second game of the second set to steal an early advantage, but any momentum gained was immediately lost as the world No. 1 broke back in the very next game.
Further breaks in the seventh and finally the ninth game sealed Sharapova's fate, dashing hopes that she could break her duck in a tournament where she has finished runner-up on five occasions.
"It wasn't easy," Williams said afterwards. "Obviously Maria plays really well, and she's done really well here, so I just decided I had to do a little better, stay focused and make more shots."
This latest defeat is the Russian's 15th in a row against the American -- a sequence which stretches all the way back to 2004.
Williams will play Li Na in Saturday's final after China's world No. 2 beat Dominika Cibulkova in a rematch of January's Australian Open title match.
It went to three sets, as did their quarterfinal clash at Indian Wells this month, before Li prevailed 7-5 2-6 6-3 against the Slovakian 10th seed to become the first player from her country to reach the Miami final.
The 32-year-old is seeking to end a run of nine consecutive defeats against Williams, the last of which was in the final of last season's WTA Championships.
"It's a good challenge, I think," she said. "Here we can really see how I've improved in these three, four months."
World No. 1 Rafael Nadal fought his way into the men's semifinals, where he will face 2010 runner-up Tomas Berdych.
The Spaniard needed to come from behind against big-serving Canadian Milos Raonic, winning 4-6 6-2 6-4 in two hours and 35 minutes.
"For me to be in semifinals after losing early in Indian Wells is very important for my confidence," said Nadal, a three-time losing finalist in the hard-court tournament.
Nadal has a 16-match winning streak against Berdych, who will return to the top five in the rankings after earlier battling past Ukraine's Alexandr Dolgopolov 6-4 7-6 (7/3) in the third quarterfinal.
It was the Czech's 450th ATP Tour victory, making him just the ninth active player to achieve that milestone.
"He was a very tricky opponent," said Berdych. "Even the conditions were not the perfect way that I really like. It was quite windy, so it was a little bit more difficult. But I handled it quite well."
World No. 2 Novak Djokovic and Japan's Kei Nishikori, who beat Andy Murray and Roger Federer respectively in their quarterfinal ties, will contest the first semifinal on Friday.