Li Na of China returns the ball during the quarter final match of Porsche Tennis Grand Prix against Petra Kvitova of the Czech Republic in Stuttgart, Germany, on April 26, 2013. Li Na won 2-0. (Xinhua/Ma Ning)

World number five Li Na withstood a late comeback from Petra Kvitova to beat the fifth-seeded Czech 6-3 7-5 on Friday and set up a Stuttgart Grand Prix semifinal with American qualifier Bethanie Mattek-Sands.

The second seed from China was put under early pressure by a series of sizzling Kvitova groundstrokes but responded by rattling off five consecutive games to snatch the first set.