Auger-Aliassime ousts former finalist Cilic to reach last eight
Auger-Aliassime downed the Croatian 27th seed Cilic -- who was Australian Open runner-up to Roger Federer in Melbourne in 2018 -- 2-6, 7-6 (9/7), 6-2, 7-6 (7/4) in 3hr 35min on John Cain Arena.
He joins Denis Shapovalov in the last eight to make it the first time two Canadian men have reached that stage at the Australian Open.
Auger-Aliassime will face either last year's finalist and second seed Daniil Medvedev or American Maxime Cressy for a place in the semi-finals.
"It's amazing. It puts my belief even higher, I lost three times to Marin in the past, this is my first win against him and in an important moment like this," the Canadian said.
"I told him at the end of the match he's a champion, the way he handles himself and the way he plays and I knew he was going to come out with his best level and test me and make me earn my win.
"So I'm really relieved and happy to get through, especially the way I did it."