Maria Sharapova was dumped out of the WTA LA Women's Tennis Championships by Flavia Pennetta in the semi-finals on Saturday night.

The 10th-seeded Italian saw off the Russian, who recently returned to action following 10 months on the sidelines with a shoulder injury, 6-2 4-6 6-3 to earn a final date with Samantha Stosur at the Los Angeles event.

Australian doubles specialist Stosur remains on course for a maiden singles title after storming into the final earlier on Saturday.

The 25-year-old, seeded 13, was far too strong for Sorana-Mihaela Cirstea and ran out a convincing 6-3 6-2 winner against the Romanian in just over an hour.