Maria Sharapova brushed aside Klara Koukalova 6-1, 6-2 in the first round of the Madrid Open on Sunday, while Ana Ivanovic beat Madison Keys 6-1, 7-6 (4).
Sharapova, who lost to Serena Williams in last year's final, converted six of eight break points to take advantage of Koukalova's eight double faults on the Caja Magica clay court.
The eighth-seeded Sharapova will play Christina McHale of the United States in the second round.
The 11th-seeded Ivanovic ousted Keys to set up a meeting with fellow Serb Bojana Jovanovski. Ivanovic overcame her shaky serve by saving three of four break points.
Top-ranked Williams opens her title defence later against Swiss Belinda Bencic.