Defending champion Aryna Sabalenka outclassed Karolina Muchova to seal a 6-3 6-4 win at the Brisbane International on Saturday and reach the final of the Australian Open tune-up tournament for the third straight year.

The world number one has been in brilliant form in her first tournament of the year and arrived for the match having defeated reigning Melbourne Park champion Madison Keys in straight sets in the previous round.

Things were expected to be trickier against Muchova, who is known for her inventive brand of tennis and had racked up a 3-1 career head-to-head record over Sabalenka, including victories in their previous three meetings.

Sabalenka shrugged off that statistic to take full control of the semi-final clash with a break in the second game, before she displayed deft touches and power from the baseline to take the first set, which she finished with a huge backhand winner.

The four-times Grand Slam champion, who is eyeing her third Australian Open trophy when the tournament begins on January 18 at Melbourne Park, was pushed harder in the next set but edged ahead again at 5-4 to wrap up the win on serve.

"There were a lot of close misses at the end of the second set, but I'm super happy to close this match in straight sets," said Sabalenka, who prevailed on her fourth match point.

"She's a great opponent and I knew that if I gave her that opportunity in the last games, she would take it, and it would be a bit trickier to play. I'm super happy I got the win."

Up next for the Belarusian is either American Jessica Pegula or Ukrainian Marta Kostyuk.

Three Americans will be in action in the men's tournament semi-finals, with Aleksandar Kovacevic facing Brandon Nakashima while their compatriot Alex Michelsen meets top seed Daniil Medvedev of Russia for a spot in Sunday's title clash.

-Shrivathsa Sridhar/Reuters