Venus Williams will play Vera Zvonareva of Russia for the title at the WTA Tour's season-ending Sony Ericsson Championships after both came through testing three-set semifinals on Saturday.
Wimbledon champion Williams saw off world number one Jelena Jankovic 6-2 2-6 6-3 in a topsy turvy match in Doha, while Zvonareva defeated fifth-ranked Elena Dementieva 7-6 3-6 6-3 in their earlier last four match, CNN reported.
Jankovic, who will end the season as number one despite not winning a grand slam this season, had gone into the match as a firm favorite after superb displays in the round-robin, but Williams had other ideas.
She raced through the first set with two breaks of service, relentlessly peppering the Serbian's forehand win before a change of fortunes in the second set.
Jankovic broke early and despite a fight back by Williams with a break of service of her own, made it one set all with further excellent play.
Seventh seed Williams re-discovered her first set touch at the start of the decider and moved into an early break.
The American came under immense pressure on her own service in the sixth game, saving four break points before confirming her advantage and never looked back.
Serving to stay in the match at 3-5 down, Jankovic played a poor game and Williams closed it out with a thumping winner to reach the final of the WTA Tour finals for the first time.
Zvonareva, at ninth the lowest-ranked player in the eight strong field, once again defied the form book to shock Olympic champion Dementieva who had beaten her Russian compatriot on the way to gold in Beijing.
"I knew I had to start to play good every single match," Zvonareva said. "I didn't have any expectations," she told Associated Press after reaching Sunday's final.
Zvonareva frustrated Dementieva with solid ground strokes in the final set. She capitalized on a string of errors by Dementieva to win the final game to love.
Zvonareva recovered from a 1-4 deficit in the first set before claiming the tiebreak on her second set point.
Dementieva also had a 4-1 lead in the second set, and this time held onto it to even the match. She said Zvonareva was a dangerous player because she played good defense, and could quickly go on the offense.
"You have to put pressure all the time," Dementieva said.