Serena Williams brushed aside Belinda Bencic of Switzerland 6-2, 6-1 to open her defense of the Madrid Open title on Sunday, while Maria Sharapova beat Klara Koukalova 6-1, 6-2 in the first round.In the men’s tournament, Novak Djokovic withdrew before the start of the event because of a right wrist injury that had already affected his play at Monte Carlo last month.”I did everything possible in order to play in Madrid,” Djokovic said. ”But unfortunately my right arm injury has flared up again.”The top-ranked Williams won nine of 10 games during one stretch to take control of her first match since taking a monthlong break following her early exit at Charleston.Williams, who has won the clay-court tournament the past two years, broke Bencic five times and rounded out her lopsided win in less than an hour with her 11th ace.Williams will play China’s Peng Shuai in the second round after she dismissed Kurumi Nara of Japan 6-2, 6-3.Sharapova, who lost to Williams in last year’s final, converted six of eight break points to take advantage of Koukalova’s eight double-faults.
