* Sharapova serves 12 aces and 11 double faults
* Azarenka surrenders after over 2 hours of baseline biffing
* Sharapova to play Serena Williams in final (Adds quotes)
PARIS, June 6 (Reuters) - Maria Sharapova turned her French Open semi-final into a game of Russian roulette, firing winners and ugly shots with equal measure as the champion bludgeoned her way past third seed Victoria Azarenka 6-1 2-6 6-4 on Thursday.
The Russian, who next meets world number one Serena Williams, served 12 aces and 11 double faults in a see-saw encounter against the Belarussian.
Second seed Sharapova raced through the opening set in less than half an hour, spraying Court Philippe Chatrier with forehand winners.
Double Australian Open champion Azarenka hit back to take the second set but lost her momentum after a 30-minute rain interruption, her opponent wrapping it up on her fifth match point after two hours 10 minutes of baseline biffing and shrieking.
"I'm really happy with the way I came out from playing a tough match yesterday. I wish I could have carried that through in two - but I did the job and I'm happy from where I was in the beginning of the tournament to where I am today," Sharapova told a news conference.
"I just hope that I can improve for the next one."
Having lost her last 12 matches against Serena, the four-times grand slam champion Sharapova will indeed need to make a dramatic improvement to become the first female to retain her title on the Paris clay since Belgium's Justine Henin in 2007.
The Russian thumped 42 winners, most of them with her devastating forehand, but a total of 39 unforced errors also meant the contest could have gone either way.
Sharapova, who lost the opening set 6-0 to Serb Jelena Jankovic in the quarter-finals, made two double faults as she dropped her serve in the first game against Azarenka.
The Belarussian was making her first appearance in the French Open semi-finals.
"Today I'm disappointed about the match and what happened out there, but overall I have to give myself credit for going one step further," said Azarenka.
"Even though I lost today I still tried to come back and tried to make something happen, which before was much more difficult for me to do."
Azarenka also needed time to settle.
By the time she realised that, Sharapova had won six games in a row in 28 minutes, allowing the third seed only seven points in the process.
Azarenka started to find better angles in the second set and opened a 40-15 lead in the third game before a couple of sharp first-service return winners reminded her she would have to fight for every point.
Dark clouds gathered in the sky as Azarenka broke to go 4-2 up when Sharapova netted a backhand.
The Russian poster girl then conceded two break points at 5-2 when the umpire called Azarenka's shot in although TV footage showed the ball was long.
Sharapova saved the first break point with an ace but double faulted on the second.
The rain then intervened and it seemed to take the wind out of Azarenka's sails.
"I think the break kind of changed the momentum," she told a news conference. "I was just trying to make things happen too quick and started missing the ball."
A backhand winner gave Sharapova a break for 2-1, only for Azarenka to break back after yet another double fault at the end of a 10-minute game.
Sharapova kept playing at a hectic pace and soon went 5-2 ahead.
Azarenka saved four match points as she broke back for 5-3 and then held serve but the title holder already had her teeth sunk deep into her prey and finished the match off with an ace. (Editing by Tony Jimenez and Alison Wildey)