Serena Williams moved one step closer in her pursuit of a 19th grand slam title, but knows the next Australian Open hurdle won’t be quite as simple to clear.

Williams crushed Belgian Alison Van Uytvanck 6-0 6-4 on Margaret Court Arena, claiming the first set in 21 minutes before Van Uytvanck found her feet on Tuesday night.

Williams began the year with an inconsistent showing at the Hopman Cup, but looked more clinical against the world No.106.

The top seed could receive a sterner test in the second round against unseeded Vera Zvonareva.

Zvonareva became the world No.2 in 2010 when the Russian reached the finals of Wimbledon and the US Open.

But she tumbled to 992nd in 2014 after spending more than a year and a half on the sidelines due to injury and illness.

“She’s on the way back. I know she’s been fighting and playing really hard,” Williams said of Zvonareva, now ranked 203rd.

“It’s going to be tough.

“It’s going to be tricky.

“She does so many things well.”

Williams stormed to a straight-sets victory over Zvonareva in the 2010 Wimbledon final, when the Russian could not force a single break point.

On Tuesday night, Williams closed out the match by breaking the Belgian’s serve in the second set.

“I had the jitters,” Williams said.

“It’s never super easy to be the one that everyone wants to beat.

“I felt ok. I definitely think I can improve a tremendous amount.”

Venus Williams, the No.18 seed, thumped Spaniard Maria-Teresa Torro-Flor 6-2 6-2.

The elder Williams, in form after downing Caroline Wozniacki in the final of the Auckland Classic, next meets compatriot Lauren Davis.

The Williams siblings will be in action together on Wednesday when they face Anabel Medina Garrigues and Yaroslava Shvedova in the doubles.

The sisters have combined to win the women’s doubles title four times at the Australian Open, including in 2003 when Serena defeated Venus in the singles final.