World number one Aryna Sabalenka stepped up her Australian Open preparations as she overpowered Marie Bouzkova in straight sets to reach the Brisbane International semi-finals on Friday. Sabalenka, who has won the last two titles at the Grand Slam in Melbourne, beat the Czech player 6-3, 6-4 in 1 hour 45 minutes. She now plays Russian teenager Mirra Andreeva, who defeated Tunisia's Ons Jabeur 6-4, 7-6 (7/2). "Her movement is really great, she's trying to get to every ball and make you play an extra shot so that's really difficult," Sabalenka said of the 44th-ranked Bouzkova.