Petra Kvitova will face Agnieszka Radwanska in the WTA Finals showpiece after ending Maria Sharapova's hopes of winning the season-ending tournament for the first time in 11 years.

Sharapova won all three Red Group matches to ease into the last four in Singapore, but the world number four came unstuck against Kvitova at the semi-final stage on Saturday.

Kvitova triumphed 6-3 7-6 (7-3) to ensure she will face Radwanska in Sunday's final, with the Czech eyeing her second WTA Finals title four years after her solitary success in the lucrative tournament.

While Sharapova had no trouble in securing her semi-final spot, two-time grand-slam champion Kvitova was indebted to compatriot Lucie Safarova for beating Angelique Kerber to see her through.

Kvitova took five of her six break-point opportunities and produced a remarkable second-set fightback to avoid being taken to a decider by Sharapova, who led 5-1 and wasted one set point before losing a tie-break to crash out. 

Sharapova gifted Kvitova a break in the opening game of the match when she sent a tame serve into the net for a double fault. 

Kvitova was unable to press home that advantage, though, as a fired up Sharapova hit straight back with a break to level against the world number five.

But Kvitova took that setback in her stride as she came up with a brilliant return to earn a break point in the seventh game and duly took a 4-3 lead courtesy of a booming forehand which Sharapova got back, but sent long.

Five-time grand-slam champion Sharapova then took a firm grip of the second set as Kvitova failed to match the standard she set in the opener.

The powerful Russian broke immediately and then again to storm into a 4-0 lead as Kvitova made life a little too easy for her and Sharapova looked set to wrap up the set with ease when she led 5-1.

But Kvitova came storming back as Sharapova lost her way and was broken to love before failing to convert a set point before the Czech broke again to win a fourth game in a row and make it 5-5 with a sublime forehand winner down the line.

From being in complete control, Sharapova found herself serving to stay in the match at 6-5 and forced a tie-break with a hold.

The momentum was firmly with Kvitova, though, as she secured three mini-breaks to set up a showdown with Radwanska, who beat Garbine Muguruza earlier in the day.