- Defending Madrid Masters champion Petra Kvitova wins first round match
- The world No. 4 defeats New Zealand's Marina Erakovic 6-2 6-3 in Spain
- Serena Williams makes light work of her first round opponent, Elena Vesnina
- Venus Williams defeated 6-4 6-1 by Germany's Angelique Kerber
Czech Petra Kvitova began the defense of her Madrid Masters crown with a comfortable victory over New Zealand's Marina Erakovic.
The world No. 4 beat her opponent 6-2 6-3 in just over an hour as she got her first taste of the controversial blue clay surface in the Spanish capital.
In a dominant display, Kvitova hit 28 winners and five aces, breaking Erakovic five times in the match.
Thirteen-time grand slam winner Serena Williams also had little trouble in her opening match, as the American beat Russia's Elena Vesnina 6-3 6-1.
After her win Williams told reporters the tournament's blue surface, which has attracted complaints from the world's top male players including Rafael Nadal and Novak Djokovic, caused her no trouble.
"I haven't noticed a difference between the blue and the red clay. I think it's the same, it's just you don't get as dirty," she told a press conference.
Williams also said she was content with her recent form, extending her unbeaten run on clay this season to eight matches.
"I was feeling good. It's my first tournament in Europe this year and I just hope I can keep up the good form," she added.
Serena's sister Venus Williams didn't make it past round two though after she was beaten 6-4 6-1 by Germany's Angelique Kerber.
No. 8 seed Li Na, from China, beat Spain's Sílvia Soler-Espinosa 6-3 6-1 while Serbian No. 15 seed Jelena Jankovic was knocked out by Carla Suarez Navarro, also from Spain.
It was a good day for the Czech Republic as three of their women made it into round two. Lucie Hradecka defeated China's Peng Shuai 6-4 5-7 6-4 while Lucie Safarova beat Estonia's Kaia Kanepi 6-4 6-4.
Andrea Hlavackova is also through after she got the better of Australia's Anastasia Rodionova 6-1 6-4.
In the men's draw, Russia's Mikhail Youzhny beat Spanish wild card Javier Marti 6-3 6-2 to reach round two, while Serbia's Viktor Troicki also advanced, defeating American Donald Young 6-1 4-6 6-1.
No. 11 seed Nicolas Almagro, from Spain, went a set down but rallied to beat Colombian qualifier Santiago Giraldo 6-7 6-3 6-3.