Russian qualifier Aslan Karatsev became the first player to reach a Grand Slam quarter-final on debut in 25 years, stunning 20th seed Felix Auger-Aliassime at the Australian Open on Sunday.

The power-hitting 27-year-old, a virtual unknown before the tournament started, battled back from two sets down to upset the Canadian 3-6, 1-6, 6-3, 6-3, 6-4 on Margaret Court Arena in what was his first five-set match. It continued his giant-killing run after blitzing eighth seed Diego Schwartzman in round three.

Aus Open, day 7 men’s roundup: Dimitrov stuns Thiem, qualifier Karatsev reaches quarters on debut

Karatsev, ranked 114, is the first Grand Slam debutant to reach the quarter-finals at a Major since Romanian Alex Radulescu at Wimbledon in 1996 and only the seventh in the Open era.

He is the first qualifier to achieve the feat since Australia’s Bernard Tomic at Wimbledon in 2011 and only the third ever at the Australian Open after Bob Giltinan in 1977 and Goran Ivanisevic in 1989.

The bearded Karatsev has been on the verge of playing a Grand Slam for years, but on nine previous attempts the injury-dogged Russian fell in qualifying. He was part of the victorious Russian ATP Cup team this month along with Daniil Medvedev and Andrey Rublev, who play their fourth-round matches on Monday.