Sharapova cruises, Kvitova battles through in Madrid
File photo shows Russia's Maria Sharapova returning the ball to Poland's Agnieszka Radwanska during their quarter-final at the WTA Porsche Grand Prix in Stuttgart, southwest Germany, on April 25, 2014 - by Thomas Kienzle
Sharapova claimed her first title of the year in Stuttgart two weeks ago and continued her return to form after a difficult start to the year to seal victory in little over an hour.
Last year's finalist in Madrid will next face unseeded American Christina McHale in the second round.
It was a more difficult afternoon for fifth seed Petra Kvitova as she need a final set tie-break to overcome Romanian Sorana Cirstea 6-1, 5-7, 7-6(7/4).
The former Wimbledon champion looked well on course for the second round after racing through the opening set, but was then broken four times in the second as the world number 27 levelled the match.
Both women were more stable on serve in the decider as it went to a tie-break after just one break apiece and Kvitova eventually had too much to set up a meeting with American Varvara Lepchenko.
Elsewhere, 11th seed Ana Ivanovic overcame Madison Keys in straight sets 6-1, 7-6 (7/4), while another American, Sloane Stephens, beat Romanian qualifier Monica Niculescu 6-2, 3-6, 6-2 to also reach the last 32.