CINCINNATI, OH, USA -- No.9 seed Aryna Sabalenka of Belarus claimed a first-round victory at the Western & Southern Open on Monday afternoon, easing past Petra Martic of Croatia, 6-1, 6-4.

"Of course I knew that [Martic is] a great player, mixing up her shots, slices, flat balls, then going up with the spin," Sabalenka said, after her win. "Mentally, I was really ready for that, I was focused. I’m happy with the level I showed today, and that was a great match."

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In the first meeting between the two Top 25 players, it was the World No.9’s power game that was on song, as she garnered the win over 21st-ranked Martic after one hour and 20 minutes of play. Sabalenka had a stellar showing in her Cincinnati main-draw debut last year, beating two Top 10 players to reach the semifinals.

Sabalenka saved all seven break points she faced in the clash, including three in the final game of the encounter. The Belarusian won 82 percent of points on her first serve and fired 31 winners, including six aces.

Sabalenka staved off a break point in the first game with a backhand winner, and then the Belarusian went on a game-winning tear with her powerful play. Another backhand winner, this one crosscourt, gave Sabalenka the first break at 2-0, and she fended off three more break points in the next game with two forehand winners and a strong serve, eventually holding for 3-0.

The No.9 seed blasted an ace to complete a hold for 5-0, then garnered two set points in the next game in hopes of obtaining the bagel. Martic came up with clutch grit to erase those chances and get on the board, but Sabalenka notched the one-set lead in the next game, closing out the opening stanza with her fifth ace.

In the second set, Sabalenka survived a three-deuce game to hold for 2-2, then put herself in front by breaking Martic directly afterwards, on the fourth break point of another protracted game.

Martic, who won her first WTA singles title at Istanbul in April, was able to hold onto her serve over the next couple of games, keeping herself in contention to pull off a comeback win. The Croat got a prime opportunity to level the set at 5-4, forcing errors from Sabalenka with gritty groundstrokes and reaching triple break point.

But Sabalenka was unflappable when facing break points all day, and she used two precise and powerful serves along with a fierce forehand to pull herself to deuce. An error-forcing backhand then gave Sabalenka a match point, and another strong serve forced a netted return from Martic to clinch victory for the Top 10 player.

"In the last game, it was 0-40, and I was like, ‘Okay, just stay aggressive, go for the big targets, and just do your best,'" said Sabalenka. '"If you lose this game, you’re still in the game, and that’s okay. She’s a great player, and she’s coming back a lot, and that’s normal.’ After that thinking, everything changed really quick. I’m happy with this mentality on the court today."

Next up for Sabalenka will be the winner of the first-round clash between Viktoria Kuzmova of Slovakia and Zheng Saisai of China. If Zheng wins, it will be a rematch of the San Jose final from two weeks ago, where Zheng upset Sabalenka for her first WTA singles title.

"In San Jose, I knew that [Zheng is] a tricky player," said Sabalenka. "I was rushing myself, I was too nervous because it was [my] first final since Shenzhen, and I really wanted it. This time, if we face each other, I think I’ll be much stronger with my head."