MELBOURNE, Australia - Former World No.1 Naomi Osaka surged through a tricky 6-2, 6-4 victory over rising Czech star Marie Bouzkova to begin her 2020 Australian Open campaign.

"It was really tough for me, trying to control my nerves," she said during her on-court interview. "I was really glad to finish it in two."

The No.3 seed was playing her first match in Melbourne since winning her second major title over Petra Kvitova one year ago, and played her best tennis in the crucial moments to advance after 80 minutes on Rod Laver Arena.

"For me it's really odd here," she continued in press. "I just feel really happy. I don't really have this mentality of, I'm, like, defending now. It's really weird.

"But I'm very thankful for it, because I think if I did go into the match with that, I would have been more tense."

Osaka arrived in Melbourne as defending champion for a second straight major tournament, having finished her US Open title defense in the fourth round last summer. Looking more at ease than she did in Flushing Meadows, Osaka enjoyed a serene start on Rod Laver Arena, taking on Bouzkova, a former junior US Open champion who pushed 23-time Grand Slam champion Serena Williams to three sets in the semifinals of the Rogers Cup in August, for the first time.

"For me, I've never played her before, so it's tough to play someone you've never played in the first round of a Grand Slam," she trails off, adding with a gasp, "Oh my god, she's younger than me! So that's really tough too. I just know that she's going to become a great player and we're going to play a lot of really hard matches."

Bouzkova looked to have Osaka on the back foot when she put down two confident service holds and engineered the first break point of the match. The No.3 seed responded in emphatic form, saving the break point and racing out to a 0-40 lead in the very next game.

Though the Czech youngster pushed things back to deuce, Osaka was undaunted, breaking at her fifth opportunity and promptly taking a 5-2 lead behind her trademark aggression. She ultimately sealed the opening set with a searing cross-court forehand winner - her 13th of the day.

Bouzkova was making her main draw debut at the Australian Open - falling in the final round of qualifying back in 2018 - and continued fighting early in the second set, earning two more break points on Osaka's serve and staving off one on her own before forging ahead 4-2.

Osaka went on another roll from there, winning three straight games and blasting a powerful backhand to put her within four points of victory. Serving for the match, she held to 15 to the delight of the Aussie crowd.

"You probably didn't come for me, but thanks for filling up the stadium," she joked.

In all, she struck 29 winners to 28 unforced errors, dropping just 10 points behind her first serve while converting a solid four of nine break point opportunities. Bouzkova made 12 winners of her own but wasn't as successful on break point chances - converting just one of six - and was decidedly at a disadvantage on second serve points, with Osaka winning more than half.

"I understand that I don't have to play perfect in the first round. It's more about building your level up and getting comfortable with yourself.

"That's one of the biggest things I have learned. Also, just understanding that every match you play is probably going to be very difficult and being okay with that."

Up next for the defending champion is China's Zheng Saisai, who won the biggest title of her career last summer at the Mubadala Silicon Valley Classic. Zheng was an early winner on Monday, defeating Russian qualifier Anna Kalinskaya - who stunned former US Open champion Sloane Stephens on Arthur Ashe Stadium last year - in straight sets.

"I think I played Saisai once a couple years ago, and she's a very tricky player. She slices and dropshots from what I could see of her matches in the past.

"I think it will be probably a match where I have to dictate a lot and just stay consistent and be positive. Because there are going to be times where I do think I'll be frustrated."

2020 Australian Open highlights: Osaka outbattles Bouzkova