World number one Ashleigh Barty has earned safe passage through to the third round of Wimbledon via a clinical straight-sets win over Belgian Alison Van Uytvanck.

Key points: Ashleigh Barty lost just four games in booking her berth in the third round

Ashleigh Barty lost just four games in booking her berth in the third round Barty dropped serve once but secured five service breaks against Alison Van Uytvanck

Barty dropped serve once but secured five service breaks against Alison Van Uytvanck She has only reached the third round of Wimbledon once before, at last year's tournament

Barty triumphed 6-1, 6-3 in just 54 minutes on court two, displaying the confidence that has come with winning her first major at the French Open and assuming the top ranking in the world.

Her win over Van Uytvanck follows her first-round victory China's Zheng Saisai on Tuesday night (AEST) and is her 14th in a row.

Fellow Australian John Millman also advanced to the third round, winning his singles match against Serbian Laslo Dere 6-3, 6-2, 6-1.

Barty next plays British wildcard Harriet Dart on Saturday with a huge opportunity to embark on another deep run at a major.

"What happens in the rest of the draw is up to everyone else," Barty said.

"It's not up to me."

Van Uytvanck reached the final 16 at Wimbledon last year and loomed as a dangerous opponent for the top seed.

Barty, though, assumed control from the outset, breaking the Belgian twice to charge to a 5-0 lead.

She wrapped up the first set in 25 minutes before breaking Van Uytvanck for a third time early in the second set.

When landing her first serve Barty conceded just five points all match and dropped serve only once — when trying to close out the contest at 5-2 in the second set.

She hit 14 winners and committed a meagre seven unforced errors in matching her Wimbledon-best run to the third round from last year.

"It was still tough," Barty said.

"It just wasn't tough by what everyone expected and spoke about in regards to seedings."

Wimbledon draw opens up for Barty

Two matches into her campaign and Barty's draw is already opening up like it did in Paris.

The shock first-round exits of 2017 Wimbledon champion Garbine Muguruza and world number 22 Donna Vekic have left Barty with a seed-free passage through to at least the second week.

Barty plays a forehand return during her straight-sets victory. ( AP: Ben Curtis )

Swiss 13th seed Belinda Bencic looms as Barty's highest-ranked possible last-16 opponent before a potential heavyweight quarter-final showdown with either seven-time champion Serena Williams or German titleholder Angelique Kerber.

All the talk after last Friday's draw was of Barty's quarter from hell featuring four former world number ones and four All England Club champions, among a total of seven major winners in her section.

But four major singles champions from Barty's pocket — Muguruza, Maria Sharapova, Svetlana Kuznetsova and fellow Australian Samantha Stosur — have already been eliminated.

Barty was also slated to strike a succession of big guns in Paris, but her supposed perilous draw never eventuated as the 23-year-old marched to Roland Garros glory only needing to beat one seed en route to the title, world number 14 Madison Keys in the quarter-finals.

Elsewhere, American Steve Johnson got the better of 20-year-old Alex De Minaur, beating the Australian 3-6, 7-6 (7/4), 6-3, 3-6, 6-3 in three hours and 21 minutes.

De Minaur, the 25th seed, was able to convert only three of 10 break points while Johnson made up for his 45 unforced errors by hitting 49 winners to advance.

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