Serena Williams strolled to a 6-2 6-2 victory over Columbia's Catalina Castano in the second round of the US Open in her bid to capture a second Grand Slam this year.
Her elder sister Venus, seeded 10th, also advanced with a 6-1 6-3 triumph over Maria Kirilenko, who had just four winners and committed 17 unforced errors.
Kirilenko gave Serena quite a fight last year at the French Open, taking a 4-2 lead in the final set before losing.
Venus awaits 20th seed Daniela Hantuchova in the third round after the
Slovakian crushed Maria Emilia Salerni of Argentina 6-1 6-0.
