Former World champion Ruslan Ponomariov of Ukraine overcame a point's deficit to put it across Russian Vladimir Malakhov in the rapid tie-break games and enter the World Chess Cup final, in Khanty Mansiysk, Russia.
He will take on top seed Boris Gelfand of Israel in the title round.
Gelfand qualified after disposing off Ponomariov's compatriot Sergey Karjakin 2-0 in games under normal time control.
Ponomariov had drawn both the rapid games and Malakhov was the early winner in the first tie-break game, taking control of the match with black pieces.
But Ponomariov, who holds the distinction of being the youngest ever World champion, fired back with vengeance in the second game with black and equalised before winning the remaining two games to clinch the match 4-2.
At 41, Gelfand is around 15 years older than Ponomariov, who has now established himself as a fine exponent of the knock-out format. It may be recalled that Ponomariov had won the World championship in 2001-02 ahead of Viswanathan Anand when the championship was played on the knock-out format only.
The Ukrainian hasn't had any spectacular successes otherwise in top events.
Gelfand is a seasoned campaigner, whose moment of big-glory is knocking now. Before the World Cup, only a few were backing Gelfand for a final spot despite his top seeding on ratings.
The final begins on a four-game basis, which is longer than the current two games that the players had to play till now. In the event of a tied result, there will be games under normal time control to determine the winner.