He also upset 20th seed Félix Auger-Aliassime after dropping the first two sets and coming back to win in 5 to become the first qualifier to reach a Grand Slam quarterfinal since Bernard Tomic at Wimbledon 2011, and the first man to reach a quarterfinal in his Grand Slam debut since Alex Rădulescu in 1996 Wimbledon.[21][22] He then defeated the former No. 3 player Grigor Dimitrov in four sets to reach the semifinals.[23] By doing this, Karatsev became the first qualifier to reach the semifinals of a Grand Slam since Vladimir Voltchkov in 2000 Wimbledon and the first to do so at the Australian Open since Bob Giltinan in 1977, the lowest-ranked player to reach a Grand Slam semifinal since Goran Ivanišević in 2001 Wimbledon, and the first player to reach a Grand Slam semifinal on debut in the Open Era history.[4][24] There, he lost to world No. 1 and eventual champion Novak Djokovic in straight sets.[25][26] His run at the tournament raised his ranking from World No. 114 to a career-high of World No. 42.