Naomi Osaka got her Australian Open title defense off to a stellar start. The reigning champion and No.13 seed moved past rising Colombian Camila Osorio 6-3, 6-3 in the first round on Rod Laver Arena.

The former World No.1 Osaka, who won the Australian Open in 2019 as well as last year, took 68 minutes to quash the challenge from 20-year-old Osorio, who is currently sitting at a career-high ranking of No.50.

Words from the winner: "I thought it was really amazing to play against [Osorio]," Osaka said in her post-match press conference. "She was loud, she was fighting. I think that's something special. I really commended her for that. I thought she had a great return. She was really bold. She kind of stepped in really close to the line.

"I think I was pretty solid. I think I was up 5-0 and had a little dip, but I was fortunate enough to close it out. I think that's something that I hope I'm not in that position in my next match. If I am, I already did it this time around, so I guess I'll learn from it."

Fast facts: Osorio was one of the top ranking movers of 2021, having won her first WTA singles title last year on home soil in Bogota. In her first Australian Open main-draw appearance, the young Colombian got to face two-time champion Osaka on the largest court at Melbourne Park.

But in their first meeting, it was Osaka who powered her way to victory. She improved to 17-1 in her last 18 matches at the year’s first Grand Slam event. Osaka is also now 19-2 in Grand Slam first-round matches throughout her career.

Key moments: Osaka swept to a 5-0 lead in the first set behind her impressive groundstrokes, but Osorio tried to take on the Osaka second serve more as the set progressed and was rewarded with three consecutive games.

At 5-3, Osorio had two break points to pull back on serve, but Osaka used her fierce forehand and superb serve to extricate herself from that situation, and she wrapped up the set then and there after 30 minutes.

Osaka earned the first break of the second set to lead 2-1, and it was smooth sailing for the four-time Grand Slam champion from there as she eased through the remainder of the match without facing any more break points.

Osaka finished the match with an excellent 83 percent success rate behind her first serve, and she converted four of her six break points to take home the win.

Sakkari - 2022 Australian Open 1R

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Sakkari ousts Maria in opener

No.5 seed Maria Sakkari was the first Top 10 player to move into the second round of the 2022 Australian Open. The Greek defeated Tatjana Maria of Germany 6-4, 7-6(2) in the first match of the event on Rod Laver Arena.

Seeded in the Top 10 at a Grand Slam for the first time in her career, Sakkari took 1 hour and 46 minutes to fend off the former Top 50 player Maria, who played the Australian Open on a protected ranking of No.100. This was Maria's first Grand Slam appearance since the 2020 US Open.

Maria had beaten Sakkari in their only previous encounter, at an ITF Challenger event in Mexico in 2014, when Sakkari was 19 years old and ranked outside of the Top 300. Now a member of the upper echelon, Sakkari got her revenge, but was still tested by a game Maria.

"I didn't feel great out there, but I found a solution, found a way to win," Sakkari said afterward. "She has a tricky game that sometimes it makes you feel uncomfortable inside the court. Yeah, it was a decent match. I kind of, like, survived."

Maria matched Sakkari in aces with four, but Sakkari was ultimately the more aggressive player, with 13 more winners than the German to help her clinch two close sets.

A double fault by Maria on break point at 4-4 in the first set gave Sakkari the crucial service break, and she served out the opener from there. In the second set, Maria had three break points but could not convert any, and Sakkari dominated once they moved into the tiebreak, ending the match with a forehand winner.

Read more: Five things to know about Zheng Qinwen

Sakkari will meet surging Chinese qualifier Zheng Qinwen in the second round. The 19-year-old Zheng, who made her first WTA semifinal two weeks ago at Melbourne Summer Set 1, outlasted Melbourne Summer Set 2 runner-up Aliaksandra Sasnovich of Belarus, 6-3, 1-6, 7-6(5) in the first third-set super-tiebreak of the tournament.

Svitolina slides past Ferro

No.15 seed Elina Svitolina of Ukraine also advanced into the second round, besting Fiona Ferro of France, 6-1, 7-6(4) in 1 hour and 32 minutes.

In their only prior meeting, Svitolina defeated Ferro during her run to her lone title of 2021, at the WTA 250 event in Chicago. Svitolina collected her second straight-sets win over Ferro on Monday in Melbourne, converting four of her eight break chances.

Svitolina, a two-time Australian Open quarterfinalist in 2018 and 2019, will play another Frenchwoman in her second match. Harmony Tan knocked out Yulia Putintseva of Kazakhstan 6-3, 6-3 to set up a clash with Svitolina.

Bencic, Anisimova, Giorgi among other early winners

Reigning Olympic gold medalist Belinda Bencic also won her opening-round match Monday. In a battle between former Top 10 players, No.22 seed Bencic of Switzerland defeated France's Kristina Mladenovic 6-4, 6-3 in an hour and a half.

The pair had squared off seven times before with Mladenovic holding a slim 4-3 head-to-head lead coming into this latest meeting. But Bencic was able to tie up the rivalry after converting four of her six break points in the match.

"I think we know each other well, [me and] Kristina, so we are reading each other's game very well," Bencic said. "It was kind of tricky, but I'm happy I kind of stayed solid. I don't think I played my best tennis. I'm not quite there yet, but I'm very happy with how I managed to kind of stay in the match in the important moments."

Bencic will next face Amanda Anisimova of the United States. Anisimova, who won her second career WTA singles title two weeks ago at Melbourne Summer Set 2, battled past Dutch qualifier Arianne Hartono 2-6, 6-4, 6-3.

Last year's WTA 1000 champion in Canada, No.30 seed Camila Giorgi of Italy, dismissed Anastasia Potapova of Russia 6-4, 6-0. Giorgi won the final eight games in a row.

"I think it was a great match because it was [my] first one of the year, so I think it's very important to get the rhythm," Giorgi said in press after her win.