Maria Sharapova into WTA Championships semi-finals

Maria Sharapova has reached the semi-finals of the WTA Championships in Istanbul thanks to a hard-fought three-set victory over Agnieszka Radwanska.

The triumph, which saw both players battle it out for over three hours, has seen the Russian join Serena Williams in the last four of the tournament.

World number two Sharapova lost the opening set 5-7 but was able to level the contest by taking the second 7-5.

The turnaround was complete for the French Open winner when she saw off the fourth seed 7-5 in the third.