ROME, Italy - In a first-round battle of unseeded big names, Naomi Osaka was relentless in overpowering Victoria Azarenka 6-0, 6-3 at the Internazionali BNL d'Italia in just one hour and 13 minutes.

For the Indian Wells champion, the win was sweet revenge for her only previous encounter with Azarenka - in the third round of the 2016 Australian Open, where her Grand Slam debut was unceremoniously halted by the Belarusian 6-1, 6-1.

"My original goal was to do better than I did last time," Osaka said after the match. "I wasn't really thinking much after I won the first game. I just really tried to keep the momentum going, and I was really glad that I was able to finish it at that score line.

"It didn't really feel like it was as easy as I think people think it was. I'm just really glad I was able to play an opponent like her. Just to even have a chance I think is really great, and I think it was fun."

Osaka began by firmly dispelling any doubts about her ability to power through the slow clay of the Foro Italico. Hitting crisply and cleanly, four forehand winners before the first changeover enabled the Japanese No.1 to jump out to a 3-0 lead.

By contrast, Azarenka committed seven unforced errors and one double fault in the same time frame.

Playing only her second red clay match of the season following last week's first-round exit in Madrid to Zhang Shuai, Osaka's live arm was on full display as she continued to go from strength to strength.

Teeing off on forehands at will, the 20-year-old's shotmaking in the fourth game drew gasps from the crowd - and within 16 minutes, she was up 5-0, having allowed her opponent only seven points.

Azarenka had only been bagelled seven times in her career before today - and despite fending off two set points, another forehand drifted wide to seal the two-time Australian Open champion's eighth.

Osaka thus joins Kristina Barrois (Estoril 2006), Svetlana Kuznetsova (Miami 2008), Dinara Safina (Montréal 2008), Kim Clijsters (Miami 2010), Petra Kvitova (Wimbledon 2010), Agnieszka Radwanska (Australian Open 2014) and Lauren Davis (Indian Wells 2014) as the only players ever to have inflicted a 6-0 set on the former World No.1.

As befitted a player of her stature, though, the 28-year-old came out for the second set determined to make amends. Hitting with greater depth and with renewed ferocity on her backhand wing, Azarenka broke immediately and took a 2-0 lead herself.

But Osaka's form was irresistible. The youngest player in the Top 30 dealt with Azarenka's attempts to switch things up with slice in short order, pummeling a backhand winner down the line in response; and the World No.84's second double fault of the day saw her concede her lead from 40-15 up in the fourth game of the set.

By now, Osaka was once again in full flow as her winner tally for the day reached a total of 20. Not only did her groundstroke pace seem effortless, but she was able to raise her game whenever Azarenka seemed as though she might have a shot at a turning point.

The Miami semifinalist, battling hard, made her way to three break points as Osaka attempted to serve the match out - only for the World No.21 to come up with a brilliant lob and then her third ace of the day to snuff them out.

A few points later, it was back to basics for Osaka, pounding forehands from one half of the court to the next until Azarenka could retrieve no more.

The emphatic win over the former World No.1 sets up a meeting for Osaka with none other than the current World No.1, Simona Halep in the second round - and she'll have good memories of the last time they played, a 6-3, 6-0 beatdown in the Indian Wells semifinals in March.

"I had the chance to play her in the French Open one time, and she played really good," Osaka said of facing the World No.1 on what is her most successful surface.

"I think that I played good, too, that day, and I practiced with her in Madrid, actually. I feel like she moves really amazing on clay, and just seeing how that's going to go because it's definitely not like Indian Wells, this surface. I just think it'll be very interesting."