* Sharapova to play for first title in over a year
* Dementieva exacts some grand slam revenge
* Williams stunning collapse
(Adds late match, quotes)
TORONTO, Aug 22 (Reuters) - Russia's Maria Sharapova took another big step in her comeback at the Toronto Cup on Saturday reaching her first final in more than year with a gritty 6-2 4-6 6-4 over Alisa Kleybanova.
Playing for a title for the first time since Amelia Island in April 2008, Sharapova will try to confirm her return from shoulder surgery with a victory when she takes on compatriot Elena Dementieva in Sunday's final.
Fourth seeded Dementieva advanced to her fourth final of the year with a clinical 7-6 6-1 win over world number two Serena Williams.
"Coming back after not playing for a while is always tough, especially after you've had an injury," Sharapova told reporters. "I'm really grateful I have another chance to be in a final and with the way I've been able to learn from every match.
"It's almost like another step in my career."
Working her way back after nine months recovering from shoulder surgery, Sharapova launched her comeback in May and has been at her battling best on the Canadian hardcourts even if her game still needs sharpening.
The three-time grand slam winner continues to struggle with her serve offering up 12 double faults and was only able to convert 5-of-22 break opportunities against Kleybanova but made up for those shortcomings with her tenacious competitiveness.
Her 20-year-old opponent also did not lack for grit giving the former-world number one all she could handle despite having to recover from a marathon three hour, 16 minute, three-set victory over fifth seed Jelena Jankovic on Friday.
Saturday's match lasted more than 2-½ hours.
"You have to expect her (Kleybanova) best tennis, to come out with nothing to lose," said Sharapova, who is guaranteed to be seeded at the U.S. Open moving up from her current ranking of 49 into the top 32.
"She beat a top player yesterday so she's coming off a confidence booster and came into the match playing her heart out."
Williams, who dashed Dementieva's grand slam dreams on her way to winning this year's Australian Open and Wimbledon titles, was swept off the court by the fourth seeded Russian.
The match produced little of their drama of their memorable Wimbledon semi-final won by Williams 8-6 in a third set thriller.
Williams, who had faced only one break point all week, was broken three times in the opening set, which was won 7-2 in a tiebreak by Dementieva.
In stunning collapse, a punchless Williams went from 5-3 up serving for the first set to holding her serve just once more the rest of match.
The Russian, who beat Williams in the quarter-finals at last year's Beijing Olympics on the way to the gold medal, raced into a 3-0 lead in the second and never looked back.
"I was really waiting for this match after Wimbledon," Dementieva told reporters. "It's always interesting to play Serena, especially looking for revenge after Wimbledon.
"No matter if I'm playing a grand slam or another tournament I'm expecting a tough match against her.
"I realise I have to play my best or I'm going to be out."
(Editing by Greg Stutchbury; To query or comment on this story email email@example.com)