Fnatic vs Envyus - Esl One Cologne 2015 Finals Fnatic made a comeback from 15-10 to 15-19)
Liquid vs Ence - IEM KATOWICE 2019 (Ence made a comeback from 15-9 to 16-19)
Faze vs Liquid - Starseries I-league S4 (Faze made a comeback from 12-0 to 26-28)
Mousesports vs Astralis - Esl Pro League S10 ( Mousesports made a comeback from 14-8 to 14-16)
CLG vs Renegades - ELEAGUE Major ( CLG made a comeback from 15-5 to 15-19)
Faze vs Astralis - IEM Sydney 2018 ( Faze made a comeback from 10-0 to 14-16)
Please don't say Liquid vs Luminosity because that wasn't a comeback only but that was a pure choke by Liquid :(
Im going to side with Liquid-Ence Katowice miracle.
Considering that Ence was such an underdog in the whole tournament, and because that comeback was so intensive that even casters lost their minds couple times.