BRISBANE, Australia - No.3 seed Naomi Osaka outlasted an in-form Maria Sakkari to begin her 2020 season, 6-2, 6-7(4), 6-3 at the Brisbane International.

"I knew going into it that it was going to be a really hard match," she said during her on-court interview. "I think in the second set, I was just complaining a lot in the tie-breaker. I was just trying to calm down and stay positive."

The two-time Grand Slam champion breezed through the opening set but was made to work as Sakkari edged through a tense tie-break. Striking a whopping 16 aces through the clash, she ultimately emerged victorious after two hours and seven minutes on Stadium Court.

Osaka was playing her first match since the Shiseido WTA Finals Shenzhen, where she was forced to withdraw due to a right shoulder injury during the round robin stage. She spent the subsequent off-season alongside new coach Wim Fissette, who has worked with the likes of Kim Clijsters, Simona Halep, and Victoria Azarenka.

Across the net was the 24-year-old Sakkari, who making her 2020 debut after finishing an impressive 2019 at the Henquin Life WTA Elite Trophy Zhuhai. The pair were playing for a fourth time, with the former World No.1 having taken two of their first three encounters, including their only meeting last season at the Nature Valley Classic in Birmingham - which also went three sets.

"I think I got off to a better start and was able to apply the things I wanted to," Osaka told the media. "In the second set, she knew what to expect, so she wasn't fazed by how hard I was hitting. She got more used to it and more comfortable, so it was a bit harder to win the points as easily as I did in the first set.

"In the third set, I think I just wasn't as tired because she was the one that was moving more than me."

Sakkari was the first to step up in the opening set, engineering a pair of break points as the reigning Australian Open champion struggled to rein in her powerful ground game. The Japanese youngster soon settled and soon turned the set her way, racing reeling off the final five games and serve it out at love.

The second set saw both play solid on serve, allowing neither a break point through the first 11 games. Sakkari managed slight openings as Osaka twice served to avoid a decider, but Osaka shut the door both times, rallying from 0-30 down in the latter to force a tie-break.

The unseeded Sakkari caught fire in the Sudden Death, winning five points on the bounce to earn a slew of set points, converting her third as Osaka netted a forehand to level the match.

She continued that momentum early in the final set, breaking to love for the first time thanks to an emphatic backhand return winner, and backed it up in a service game that twice went to deuce.

Osaka was strong in her reply, drawing level as she forced a forehand error from the Greek star and breaking serve once more to move within a game of victory. Shaking off a double fault on her first match point, she made no mistake on her second to book her spot in the second round.

"I'm really with how I served," she admitted when asked to grade her performance. "I had to retire from my last match because of my shoulder injury, so I wasn't really sure how I was going to serve today, but I was told I hit 16 aces, so that's pretty good for me.

"Return could be better, but it's not anything that is so extreme that I'm nitpicking at it right now.

"I think I learned a lot during the match as it went on, so hopefully that skill kind of hones during this entire tournament."

Up next for the World No.4, who reached the semifinals of this event in 2019, is rising American star Sofia Kenin, who eased past Latvian veteran Anastasija Sevastova in straight sets.

"She's like the girl that was younger than me but was better than me!" she said of her long-time acquaintance. "In the juniors she used to kill everybody.

"I didn't really play juniors, but in the times that I did, she was like the one winning everything.

"I think it's cool because we both come from the same place.

"I played her in Cincinnati and she was playing really well. That match was pretty fun to see how far we had both come."

2020 Brisbane Highlights: Osaka outlasts Sakkari