Daria Kasatkina and Margarita Gasparyan fended off two of the great stalwarts of Russian tennis to set up a final showdown at the St Petersburg Ladies Trophy.

Kasatkina recovered from a slow start to overcome fourth seed and two-time grand slam winner Svetlana Kuznetsova, after Gasparyan saw off former Wimbledon and US Open runner-up Vera Zvonareva.

Zvonareva, 36, and Gasparyan, whose promising career has been disrupted by injury, were both allocated wildcard entries to the tournament and seized advantage to reach the last four.

Gasparyan, a 26-year-old whose single-handed backhand is an unusual sight in modern tennis, came through the clash with Zvonareva a 6-3 7-6 (11-9) winner to reach her first final at WTA 500 level.

The world number 126 will tackle former top-10 star Kasatkina for the title, after the 23-year-old Barcelona resident scored a remarkable 1-6 6-0 6-2 win over Kuznetsova in the second semi-final.

It was a flat Kasatkina who surrendered the opening set, but she then dashed off eight games in a row, levelling the match and surging to a 2-0 lead in the decider, knocking the stuffing out of 35-year-old Kuznetsova's challenge.

Kasatkina, a 23-year-old with more variety than most, had also dropped the first set 6-1 in her quarter-final win over second seed Veronika Kudermetova on Friday before finding her best game.

She said on Amazon Prime: "Well, why not, if losing the first set will guarantee me victory, why not?"

Kasatkina, the eighth seed this week, won the Phillip Island Trophy in Melbourne last month so is chasing a second WTA title of the year.

She is relishing the clash with Gasparyan, saying: "It's cool to have players of different styles. Tomorrow's a final so you've just got to go out there and try to show your best tennis."

An all-Russian final was already guaranteed, given the host country locked down all four semi-final places, and it will be the 30th such WTA title match.