* Sharapova had chances with early breaks
* Williams to play for seventh Miami title (Adds quotes, detail)
By Steve Keating
MIAMI, March 27 (Reuters) - World number one Serena Williams continued her decade-long domination over Maria Sharapova with a clinical 6-4 6-3 win on Thursday to reach her ninth Sony Open final.
The rematch of last year's final produced the same result as Williams, a six-time winner on the Miami hardcourts, ran her winning streak against Sharapova to 15 matches, a stunning run that stretches back to 2004.
Sharapova and Williams, who have both achieved a career grand slam and held the number one ranking, were expected to develop into one of the great rivalries in women's tennis.
But it has not quite worked out that way with Williams winning 16-of-18 meetings between the two.
In Sharapova's 16 losses, the Russian has only managed to take two sets off the 17-times grand slam winner.
"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," said Sharapova. "There is no reason for me to have any pressure because of my results against her.
"She's an incredible champion. That's the reason she's at the top.
"She's accomplished a lot, her tennis speaks for itself and I have nothing to lose out there against her."
Proving there is no place like home, Williams, who lives an hour's drive from the Tennis Center at Crandon Park, has won the Miami event more than any other tournament, the six titles one better than her five U.S. Open, Australian Open and Wimbledon grand slam wins.
She can add a seventh Miami trophy to her collection on Saturday against the winner of Thursday's other semi-final between Chinese world number two Li Na and Slovakian Dominika Cibulkova.
"I have always felt when I'm playing at my best, then it's hard for people to beat me," said Williams, winner of 58 career singles titles. "But I have to get there, and it's hard to always be at your best.
"I think that is what's special, and that's why there is a lot of rivals now.
"I think every time you step on the court it's a rivalry. I'm just here to play tennis and, you know, play my matches."
A five-time runner-up in Miami, Sharapova had her chances to end the drought grabbing the early break in both sets but could not turn the advantage into a win.
The fourth seed stepped onto a blustery centre court looking focused and determined and was rewarded with the first break to go up 4-1.
But Williams was soon back in control breaking Sharapova twice as she swept through the next five games to take the opening set.
Sharapova also opened the second set with an early break to go 2-0 but again the 32-year-old American was ready, answering right back with a break of her own.
The Russian held serve just once more before Williams moved into high gear tearing through the last four games, putting an exclamation point on the contest by closing out the match with another break when Sharapova slammed a forehand return into the net.
"I didn't think I would be sitting here the way I was playing in the beginning of the week, so I'm excited to still be in the tournament," said Williams.
"I definitely feel better than what I did in my first couple of matches but I also feel there is a big gap for me to play even better and to be more consistent and get to the level that I was playing at a little bit last year." (Editing by Frank Pingue and Julian Linden)