Petra Kvitova's first tournament since she was injured in a knife attack at her home is over.

The two-time Wimbledon champion, who was seeded 15th, lost to American qualifier Bethanie Mattek-Sands 7-6 (5), 7-6 (5) at the French Open. Kvitova threw her racket in frustration after she double-faulted on match point, but the players warmly embraced at the net.

Kvitova returned to tennis in Paris after she was attacked in the Czech Republic in December.

Mattek-Sands, a doubles champion at Roland Garros two years ago, received treatment at the end of the first set. She came back on court with a bandage on her left thigh but did not seem hampered in her moves.

Mattek-Sands, who is back in the third round for the first time since 2013, will next face Samantha Stosur.