SuggestedLeadIn: Maria Sharapova secures hard-fought 4-6 6-3 6-4 win over Agnieszka Radwanska in their red group match at the WTA Finals in Singapore.

Script: Maria Sharapova has had an injury nightmare over the past few months. And if there were any doubts in her mind about whether she had fully recovered. They will have been eased after this grueling match against Agnieszka Radwanska at the WTA Finals in Singapore.

The fifth-seeded Radwanska took a 56-minute first set 6-4 and the signs looked like Sharapova was going lose this comeback match.

But the Russian fought back to take the second set 6-3. She hasn't lost her trademark power or passion.

And as the match approached three hours, the drama continued. Sharapova took control of the third set, but then had to see off a late Radwanska fight back to close out the set.

She did it and with it secured a first victory in the red group and a first win since Wimbledon in July.

Sharapova also faces Simona Halep and Flavia Pennatta in the group as she aims to win the WTA finals for the first time since 2004.