The world number one didn't drop a set all week, blowing opponents off court with her typical huge hitting, while also displaying more touch and versatility. She was once again comfortable in the final against a spirited Kostyuk, as she clinched the 22nd title of her career.
The two-time Australian Open champion loves playing in Australia, winning 38 of her last 40 matches there. She will now head to Melbourne to reclaim the throne after losing in a thrilling final to Madison Keys in 2025.
"Every day you go out there and prove your level, and I think this week I did it really well," Sabalenka said in her victory speech.
Looking ahead to the Australian Open, she continued: "The only thing I know is that I'll be there, I'll be fighting.
"I'll do my best to go as far as possible. And do a little bit better than last year. That's my focus."
Sabalenka claimed an early break in the first set, but Kostyuk showed her fighting spirit to bring the match back on serve. However, the Belarusian pounced to break again at 5-4, taking the first set.
The second set saw Sabalenka grab another early break, but that was all she needed as that proved to be the difference, with Kostyuk struggling to get a look in on her serve.
Despite the loss, it was a positive week for Kostyuk, defeating three top-10 players en route to the final. She had beaten just one in the entirety of 2025.
As a result, she has re-entered the top 20 in the world rankings.
There has been animosity between the pair in the past, and like other Ukrainians, Kostyuk refuses to shake hands with Russians or Belarusians because of the war in her homeland.
There was no handshake in Brisbane, and in her post-match speech, Kostyuk brought up the situation in Ukraine.
“I wanna say a few words about Ukraine. I play every day with pain in my heart. There are thousands of people who are without light and warm water right now. It’s -20 degrees outside," said Kostyuk.
"It’s very painful to live this reality every day. My sister is sleeping under 3 blankets because of how cold it is at home. I was incredibly moved and happy to see so many Ukrainian flags this week."
The Australian Open begins on January 18th.