cruised into the French Open third round on Friday, in the first match of a packed women's schedule swollen by rain delays on the previous two days.
Williams, the world number one, demolished German world number 77 Julia Goerges 6-1, 6-1 in just 55 minutes in a second-round match that had originally been scheduled to take place yesterday.
She will face either fellow American Jill Craybas or Russian 29th seed Anastasia Pavlyuchenkova for a place in the last 16.
On a day when the sun returned to Roland Garros after two days of gloom, Williams demonstrated that she is well placed to end her eight-year wait for a second Roland Garros singles title.
She was playing Goerges, 21, for the first time and the American quickly established her authority by breaking to love for a 3-1 lead, before securing a double break and then serving out for the set.
Goerges managed to produce a selection of well-placed winners in the second set but she was unable to prevent herself falling to a heavy defeat as Williams made up for lost time in style.
Justine Henin, the 22nd seed and four-time champion, was due to resume her second round match against Czech Klara Zakopalova, in which she leads 6-3, 3-2, later today.
Russian former world number one Maria Sharapova, seeded 12, resumes at 6-3, 2-2 up against Belgian Kirsten Flipkens, with last year's beaten semi-finalist Samantha Stosur of Australia, the number seven seed, due on court against Paraguay's Rossana De Los Rios.
Second seed Venus Williams faces Slovakian 26th seed Dominika Cibulkova in the third round, while third seed Caroline Wozniacki takes on Romanian 31st seed Alexandra Dulgheru, who triumphed in Warsaw last week.
Defending champion Svetlana Kuznetsova and fellow Russian Elena Dementieva are also in third-round action, with Kuzentsova meeting number 30 seed Maria Kirilenko and fifth seed Dementieva tackling Canada's Aleksandra Wozniaki.