Radwańska emerged victorious after three hours and 24 minutes, coming back from a set and 5-4 down to win 6-7 (6-8), 7-5, 6-4. The length of the match makes it the longest in WTA championship history.
Radwańska lost out to Williams at Wimbledon this year. Speaking ahead of Saturday’s semi-final she said: “I have nothing to lose playing Serena. She’s a great champion and has been playing great tennis in the last couple of weeks and months. So I’m just going to go on court and enjoy myself.”