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At the age of 27, Aslan Karatsev made a remarkable breakthrough at the 2021 Australian Open, becoming the first Russian man to reach the semifinals of a Grand Slam tournament since 2006. Despite entering the competition unseeded, he stunned the world of tennis by defeating higher-ranked opponents, including eighth seed Diego Schwartzman and 20th seed Felix Auger-Aliassime, before eventually bowing out to eventual champion Novak Djokovic.