Serena Williams beat Maria Sharapova for the 15th consecutive time, rallying in both sets for a 6-4, 6-3 victory in the Sony Open semifinals on Thursday.
Williams, seeking a record seventh Key Biscayne title, improved to 16-2 against Sharapova and hasn't lost to her favourite foil since 2004.
"I have always felt when I'm playing at my best, then it's hard for people to beat me," Williams said.
Rafael Nadal could say the same. He advanced to the semifinals by hitting a flurry of forehand winners down the stretch to beat Milos Raonic 4-6, 6-2, 6-4.
On Saturday, the No. 1-ranked Williams will try for a record seventh Key Biscayne title against No. 2 Li Na, who overcame 40 unforced errors to beat Dominika Cibulkova 7-5, 2-6, 6-3. Williams is 10-1 against Li.
No. 7-seeded Tomas Berdych advanced to Friday's semifinals, beating Alexandr Dolgopolov of Ukraine 6-4, 7-6 (3). Berdych was the Key Biscayne runner-up in 2010.
The No. 1-ranked Nadal, who is 0-3 in Key Biscayne finals, needs one more win to get there again. His opponent Friday night will be No. 7-seeded Tomas Berdych, who advanced by beating No. 22 Alexandr Dolgopolov 6-4, 7-6 (3).
Nadal has beaten Berdych 16 times in a row over the past seven years.
"This tournament is a tournament where I really feel the love of the people so much," Nadal said, "so I'm going to try my best to keep playing well."
Three-time champion Novak Djokovic will play in the other semifinal Friday against No. 20-seeded Kei Nishikori, who eliminated Roger Federer on Wednesday.
The No. 1-ranked Williams won with a superior serve and better returns. She hit nine aces and broke five times, helping her rebound from deficits of 4-1 in the first set and 2-0 in the second.
Williams earned her 14th consecutive victory against a top-10 player. Her opponent in Saturday's final will be either Australian Open champion Li Na or Dominika Cibulkova of Slovakia.
Williams first won Key Biscayne in 2002 and is the defending champion. She has worn Miami Dolphins orange and turquoise throughout the tournament and considers it her home event because she lives 90 minutes up the road.
"When I grew up I always wanted to play here," she said. "I guess I just don't want to let go. It's my favourite stop on the tour. It's home. All my friends come. So it's perfect for me."
There was no evidence of a home-court advantage at the start, when Williams failed to convert four early break-point chances and fell behind. Sharapova cracked a succession of winners from the baseline and earned applause from Williams after besting her in one exchange.
But Williams broke back when Sharapova committed three consecutive backhand errors, and gained momentum from there, sweeping the final five games of the first set.
The story was similar in the second set, and after falling behind, Williams resorted to her dominating power. She quickly won one game with two aces and two service winners during a period when she swept 11 consecutive points.
Sharapova committed groundstroke errors on the final three points, and a victorious Williams trotted to the net, her left fist leading the way. She has more victories against Sharapova than against any other opponent.
"Despite my results against her, I still look forward to playing against her because you learn so much from that type of level which she produces," Sharapova said. "You finish the match, and you know where you need to improve and the things that you need to work on."