In their marathon semi-finals which last three hours each, second-seed Kuznetsova overcame Serbian fourth seed Jelena Jankovic 5-7, 6-4 and 6-3, while eighth-seeded Dementieva walked over unseeded Italian Francesca Schiavone 5-7, 7-5 and 6-2. Kuznetsova twice took the lead in the opening set before dropping her own serve. At 5-4, she missed her match point before Jankovic came back to wrap up the first set.
In the second set, the Russian jumped to a 3-0 lead before Jankovic broke twice to streak 4-3 ahead.
However, Jankovic let her chance slip away this time as Kuznetsova claimed the next three games.
After an early exchange of breaks in the deciding set, Jankovicwaned and Kuznetsova survived three break points at 2-2 and then broke to lead 4-2.
She squandered six match points on the Jankovic serve before serving out to love for victory.
"The match was going longer and longer and I was feeling better and better. I cannot explain it," Kuznetsova said, "I was far from my best game and it was very important to stay focused because usually when I play her I have so many chances."
Dementieva and Schiavone engaged in a lengthy but entertaining rallies, some to over 30 exchanges.
Dementieva led 5-3, but she allowed the Italian, who knocked out world number one Justine Henin on Thursday, to snatch the next four games and the set.
After a series of service breaks in the second set Schiavone dropped her serve at 4-4. Although Dementieva failed to serve out the set at 5-4 she broke again to lead 6-5 and then levelled the match.
Schiavone who received treatment for a tight quad muscle, only scored seven points as Dementieva swept to a 4-0 lead in the deciding set.
"The toughest part was losing the first set," said Dementieva. "I was 5-3, serving for the set and had so many opportunities and didn't use them."
"I'm glad I was able to fight and win the second set. That gaveme so much confidence and I was finishing strongly in the third."