Petra Kvitova loses to Madison Brengle in Stuttgart

                                             Wimbledon champion Petra Kvitova suffered a 6-3 7-6 (7-2) defeat by American Madison Brengle on her return to the WTA Tour in Stuttgart.

Kvitova, 25, was playing her first WTA match since February following a six-week break for exhaustion.

The Czech did win both matches on Fed Cup duty against France last weekend but was error-strewn in Stuttgart.

Top seed Maria Sharapova takes on in-form Angelique Kerber of Germany later on Thursday.

Danish fourth seed Caroline Wozniacki, who has brought former French Open champion Arantxa Sanchez-Vicario  into her coaching team, plays Czech Lucie Safarova.

Third seed Kvitova made 22 unforced errors in the first set as the far steadier Brengle broke serve once but created six break points.

The 25-year-old from Delaware is at a career high of 43 as she enjoys her best season to date, and she broke again at the start of the second to take a grip on the match.

Brengle let a 40-0 lead and four match points slip when she served for the match at 5-4, but she recovered to dominate the tie-break and converted her sixth match point.

"I think that Madison played a solid match," said Kvitova,  who made 39 winners and the same number of errors.

"She didn't miss much and it was really difficult for me because when I had the opportunity for winners I missed. The confidence wasn't really high then and I didn't feel physically there as well.

"I was still tired probably from the Fed Cup and on the clay you need to be physically ready for it. So, that was one of the reasons as well.

"I need to be still patient and I'm looking forward to next week, which I'm going to practise on clay.