June 24 (Reuters) - Czech Petra Kvitova's comeback from a lengthy injury layoff gathered momentum on Saturday as she reached the Aegon Classic final in Birmingham after Lucie Safarova retired from their semi-final with a leg injury. Twice Wimbledon champion Kvitova, playing in just her second tournament of the year, was 6-1 1-0 up at the Edgbaston Priory Club when her Czech compatriot pulled out.
Kvitova is looking in impressive shape after her absence from the sport following a hand injury caused by a knife attack during an attempted robbery at her home in December.
Safarova was the latest player to withdraw in the latter stages of the WTA event.
On Friday, American Coco Vandeweghe retired with an ankle injury in her quarter-final against Spain's Garbine Muguruza.
In another last eight game Australian Ashleigh Barty also had a walkover, with Italian Camila Giorgi retiring with a leg injury in the first set.
Kvitova will face the winner of the Saturday's second semi-final between Muguruza and Barty. (Reporting by Simon Evans, editing by Pritha Sarkar)