Petra Kvitová won on her return to competitive action after she was stabbed at her home in December ©Getty Images

Petra Kvitová won on her return to competitive tennis action after she was stabbed at her home in December as Angelique Kerber became the first women's top seed to lose in the opening round of the French Open at Roland Garros today.

A visibly emotional Kvitová, who has not featured since an intruder posing as a maintenance man got into her home and attacked her with a knife, swept aside American Julia Boserup 6-3, 6-2 to book her place in the second round.

The 27-year-old Czech star, a two-time Wimbledon champion, put in an impressive display after sustaining a career-threatening injury to her left hand.

Kvitová, the 15th seed, only began practising earlier this month and will play either American Bethanie Mattek-Sands or Russian Evgeniya Rodina in the next round.

"It's a pleasure to be here and I'm happy I made the decision to play," she said.

"Thank you for everything, you helped me through this difficult time.

"I'm glad with how I played. 

"There are a few things to improve but what can I expect after such a long time.

"I was happy that I didn't have any pain. 

"I promised my doctor, who gave me the green light, that if I feel pain in my hand during the match or in the practice, I'm stopping immediately."

Russian Ekaterina Makarova beat world number one and top seed Angelique Kerber in straight sets ©Getty Images
Russian Ekaterina Makarova beat world number one and top seed Angelique Kerber in straight sets ©Getty Images

German Kerber made unwanted history with her first-round exit as she was comfortably beaten by Ekaterina Makarova of Russia on the famous red clay.

The world number one lost 6-2, 6-2 in an hour and 22 minutes.

The result leaves her world ranking under serious threat as Romanian Simona Halep and Karolína Plíšková of the Czech Republic could overtake her by the end of the tournament.

Lesia Tsurenko of Ukraine awaits in the next round for Makarova.

Olympic champion Monica Puig of Puerto Rico is also through as she overcame 31st seed Roberta Vinci of Italy in three sets, 6-3, 3-6, 6-2.

In the men's singles draw, Gilles Müller of Luxembourg, seeded 26th, ousted Spain's Guillermo García López 7-6, 6-7, 6-2, 6-2, while Lopez's team-mate Albert Ramos Viñolas progressed with a 6-7, 6-1, 6-4, 6-2 victory.

Sixth seed Dominic Thiem wasted little time in securing a second round berth, beating Australian Bernard Tomic 6-4, 6-0, 6-2, while another rising star in Frenchman Lucas Pouille joined the Austrian in progressing as he beat countryman Julien Benneteau in a five set epic.

Pouille trailed 2-1 but won the last two sets to clinch a dramatic 7-6, 3-6, 4-6, 6-3, 6-4 triumph.