Unseeded Alex Michelsen stunned Karen Khachanov 6-3, 7-6(5), 6-2 in the 2025 Australian Open third round. The 20-year-old American dominated the first set, resisted Khachanov's comeback in a tight second-set tiebreak, and maintained his momentum in the third set to secure a commanding straight-sets win. It is worth mentioning that Michelsen had also defeated Stefanos Tsitsipas in the first round.