This is how you actually have a Happy Halloween!!!

Kvitova back from the dead to make final

It proved a happy Halloween for Czech Petra Kvitova after she made the most of coming back from the dead to set up a title-match showdown with Agnieszka Radwanksa at the WTA Finals.

WTA Finals: Radwanska sees off Muguruza to book final berth

The double Wimbledon champion was reflecting on her year, believing her singles season was over, after losing to Garbine Muguruza in her final round-robin match on Friday, only for Lucie Safarova to beat Angelique Kerber in straight sets and send Kvitova through.

The World No 5 made the most of the unlikely semi-final chance as she produced her best display of the week to beat Russia's Maria Sharapova 6-3, 7-6(3) at the Indoor Stadium on Saturday.

"It's very weird, I have to say. Yesterday I was talking about my season, and it's still not over yet," Kvitova told reporters.

"But I'm happy for that for sure. I mean, I couldn't really believe that I going to play semi-final, now I'm in the final, which is very interesting.

"I'm really looking forward (to it). I think Aga is kind of in the same situation, so it's going to be interesting."

Radwanska also needed a favour to make the semi-finals after two opening defeats, but, like Kvitova, she overcame an opponent in Muguruza who had won all three group matches.

It means whoever wins Sunday's showdown will be the first to lift the title with a 1-2 group-stage record. The round robin was introduced in 2003.

"I think it's great that it will happen," said Kvitova, who won the WTA Finals on her debut in 2011.

"It's something new in the history. That's the sport. That's the format how we play in the groups and everything. It's very interesting.

"I think that Aga is kind of on the same level as me, that she's improving each match, so that's a little bit different (from a) normal tournament.

"I don't really like the beginning of the tournaments for sure but that's how it is. It's probably normal that I'm improving my game each match. That's happening here as well. Finally I see the final line, so that's good."

The 25-year-old Kvitova, who is sure to face Sharapova again at the Fed Cup final next month in Prague, said she had promised compatriot Safarova some beers when they returned home after she helped her through to the final in Singapore.

The tall Czech holds a 6-2 win-loss head-to-head record over Radwanska but played down the favourite tag for Sunday's finale, still baffled at how she had made it through.

"It just still feels so weird that I'm in the final. You lost and still -- it's terrible," the left hander said.