The meeting lasted 3 hours 21 minutes and ended with the score 7:6, 6:4, 6:7, 6:3.
Khachanov filed right through ten times, made one double fault and converted three out of four break points.
Tsitsipas made 18 aces, made five double faults and converted five break points out of 12.
Thus, the Greek tennis player reached the final of the tournament, where he will meet with the winner of the game between Serbian Novak Djokovic and American Tommy Paul.
The Australian Open in Melbourne will end on January 29th.
Earlier, the natives of Moscow and Minsk, Elena Rybakina and Arina Sobolenko, reached the final of the main women's tournament.