Williams, seeded fifth, notched her 16th consecutive match win with a 6-2, 6-3 romp over Francesca Schiavone in a second-round match. She is going for her fourth consecutive tournament title. If she wins the German Open, she'll take home $196,600.
No. 7-seeded Elena Dementieva and eighth-seeded Marion Bartoli also had impressive wins Tuesday. Dementieva stopped Kateryna Bondarenko 6-1, 6-2 and Bartoli was in complete control in a 6-0, 6-3 win over Lucie Safarova.
In other first-round matches Tuesday, Victoria Azarenka, beat Casey Dellacqua 6-2, 6-2; and Anabel Medina Garrigues got past Tathiana Garbin 3-6, 7-5, 2-2, as Garbin retired with left thigh injury in the third set.