Defending champ Serena Williams reaches Madrid Open 3rd round

Serena Williams from U.S. returns the ball to Lourdes Dominguez Lino from Spain during their match at the Madrid Open tennis tournament, in Madrid, Tuesday May 7, 2013. (AP Photo/Andres Kudacki) (The Associated Press)

Serena Williams from U.S. serves to Lourdes Dominguez Lino from Spain during their match at the Madrid Open tennis tournament, in Madrid, Tuesday May 7, 2013. (AP Photo/Andres Kudacki) (The Associated Press)

MADRID – Serena Williams moved her Madrid Open title defense into the third round after beating Lourdes Dominguez Lino of Spain 6-2, 7-5 on Tuesday.

Despite being unsettled by her opponent's drop-shots and lobs, top-ranked Williams moves on to pursue a fourth title of the year and 50th of her career.

Williams hasn't won much on the clay. She won on blue clay here a year ago and on green clay in the U.S. last month. She hasn't won on red clay since the 2002 French Open.

Also, Marion Bartoli of France overcame a fall to beat qualifier Maria-Teresa Torro-Flor of Spain 6-4, 2-6, 6-4.