Petrova, Azarenka into semis

STUTTGART, GERMANY.

Former champion Nadia Petrova will meet Belarus Victoria Azarenka in the semi-finals of Stuttgart's WTA event after the pair won their quarter-finals on Friday.

Petrova, the 2006 champion, had a comfortable win over China's Li Na, who knocked out world number one Serena Williams on Wednesday, and claimed a 6-2, 6-3 win in just 68 minutes

"I am just trying to have fun out there, I have changed a few things in training to keep it fresh and it seems to be working," said a pleased Petrova

Azarenka trod a much tougher path to the last four as she knocked out Olympic champion Elena Dementieva after a marathon quarter-final which lasted two hours and 53 minutes.

The 19-year-old Azarenka, came out on top over fourth seeded < Dementieva, 7-6 (8/6), 3-6, 6-1.