The Russian only secured her place in the tournament in Singapore - which features the top eight available female players in the world rankings - on Saturday (October 22) when she won the Kremlin Cup on home soil in Moscow.

In a dramatic match the former Australian Open and US Open champion beat the Polish world number three 7-5, 1-6, 7-5 in the white group contest.

Fans had looked on stunned when she gave herself an impromptu haircut in the third set, removing part of her ponytail in what seemed to be a rage.

Later in the set she appeared to be in tears but somehow still managed to keep her composure to win.

Radwanska squandered her match point while 5-4 up in the decider with a backhand into the net and was duly punished.

The second white group clash on the hard courts of Singapore's Indoor Stadium proved to be equally thrilling as Czech world number five Karolina Pliskova also saved match point en-route to beating Spain's number six seed Gabrine Muguruza.

Pliskova downed the French Open champion after a thrilling affair, 6-2, 6-7, 7-5.

The red group will play their second matches tomorrow, with Romania's Simona Halep playing Germany's world number one Angelique Kerber after both won their first contests.

American Madison Keys will meet Slovakia's Dominika Cibulkova in the other clash.

The top two players from each group will move on to the semi-finals.