By Patrick Johnston
SINGAPORE (Reuters) - U.S. Open champion Flavia Pennetta kept alive her WTA Finals bid with a flurry of backhand winners as she downed a strapped up and fatigued Agnieszka Radwanska in straight sets on Tuesday.
The Italian, who said she will retire after the tournament, struck her 11th backhand winner crisply down the line on her fourth match point to seal an impressive 7-6(5) 6-4 victory over the Pole at the Singapore Indoor Stadium.
It was Pennetta's first win in the Red Group after she was blown away by top seed Simona Halep of Romania 6-0 6-3 in her opener on Sunday. The Italian said a pep talk from her coach had proved the difference.
"(He) just came in the court and told me to be more aggressive, to be more with my backhand more than my forehand," the 33-year-old Italian told reporters.
"He just told me... 'keep going and try to go for the shot'."
Halep faces Maria Sharapova later on Tuesday where a victory for the Romanian would eliminate Radwanska, who was beaten by the Russian in her opener and looked weary after a hectic recent schedule in a bid to qualify for the eight-woman finals.
"The concentration was really slipping away sometimes and I wasn't focused enough," Radwanska said.
The Polish world number six had started brightly, twice holding a break in the first set but was broken when trying to serve it out at 5-4 and Pennetta's dominant backhand took control as the Italian prevailed in the tie-breaker.
Pennetta had a worrying moment in the tie-breaker when she appeared to hurt her ankle and needed a medical time out in the third game of the second set because of blisters but the issues failed to halt her ambition.
She crushed 37 winners against an increasingly deflated Radwanska, who played with a heavily tapped shoulder, and secured the sole break in the seventh game with a powerful backhand return before confidently riding out winner.
(Editing by Sudipto Ganguly)