WIMBLEDON champion Maria Sharapova advanced to the final of the WTA and ATP Masters Series tournament with a 6-4 6-3 victory over Venus Williams.
The second-seeded Russian largely dictated their rallies, but the eighth seeded American fended off two match points before Sharapova was able to put her away.
Trailing 5-2 in the second set, Williams fought off one match point against her serve with an ace, then went on to hold and keep the set alive.
In the ninth game the determined American put Sharapova on the defensive at 0-40, but the Russian held her nerve, fighting off those three break points as well as one more before getting her next opportunity to claim the match, on which she netted a forehand.
Sharapova, 17, had to save two more break points before she got another chance and put away the match after 1hr 17min.
The second-seeded Russian now awaits the winner of the second semi-final in which top-seeded Amelie Mauresmo of France faces a dangerous encounter with unseeded Belgian Kim Clijsters.
"At this point I don't care who I play," said Sharapova, minutes after beating Williams. "I'm in the final and I feel fantastic."
Williams, who defeated her sister Serena, the three-time defending champion, in a scintillating quarter-final Wedneasday (AEST), said she felt flat from the beginning.
"The first problem for me was just I was so tired," she said. "I don't know why. I'm not usually tired. I think sometimes I went for a shot too quickly because my energy level was low. I had some bad shot selections."
Clijsters, a former world No.1 whose ranking plunged as she was sidelined for much of 2004 by a wrist injury, has belied her unseeded status for the second tournament in a row.
She won the title at Indian Wells, California, two weeks ago, beating world number one Lindsay Davenport in the final.
Her victims here have included 12th seeded Nathalie Dechy of France, fifth-seeded French Open champion Anastasia Myskina of Russia and fourth-seeded Russian Elena Dementieva.
Clijsters is 14-1 this year and has won her last six matches against Mauresmo, the most recent a straight-set victory in the final of the 2003 WTA Tour Championships.
Adding spice to their semi-final is the fact that should Mauresmo advance and then go on to beat Sharapova for the title, she would regain the world number one ranking.
However, should Mauresmo fall to Clijsters, and Sharapova go on to win the title, the Russian will claim the world number two spot.
On the men's side on Thursday, world No.1 Roger Federer continued his pursuit of a first Key Biscayne title, taking on sixth-seeded Briton Tim Henman in a quarter-final clash.
Federer has won 28 of his 29 matches in 2005, the only blemish on his record a semi-final loss to eventual champion Marat Safin at the Australian Open.
Since then, Federer has won 19 straight matches, and he has claimed four ATP titles this year.
The men's quarters will conclude with ninth-seeded Andre Agassi, a six-time titlist at this event, taking on fellow American Taylor Dent.