Learner Tien celebrated his shock Australian Open victory over three-times runner-up Daniil Medvedev in true teenage fashion, seeking out a well-earned pizza after edging a five-set thriller to progress to the third round.

Fifth seed Daniil Medvedev is out of the Australian Open after losing a five-set thriller to teenager Learner Tien in the biggest upset of the tournament so far.

Learner Tien pulled off a massive upset against Daniil Medvedev at the Australian Open. So, who is Tien, the 19-year-old out of California?

Learner Tien has stunned the tennis world, claiming an upset victory over Daniil Medvedev at the Australian Open.

American teenager Learner Tien produced arguably the biggest shock of the Australian Open so far as he defeated last year’s runner-up Daniil Medvedev in five sets, 6-3, 7-6 (4), 6-7 (8), 1-6, 7-6 (7).

Learner Tien triumphs in a late-night classic over Daniil Medvedev, with the American qualifier sending the No.5 seed home in a five-set marathon that finished close to 3am on Friday.

Teenage qualifier Learner Tien stunned last year's Australian Open runner-up Daniil Medvedev in an epic match ending at nearly 3:00 am Friday after defending champion Jannik Sinner roared back to take his place in the third round.

American qualifier Learner Tien enjoys a pepperoni pizza after defeating former world number one Daniil Medvedev in a five-set match that didn't finish until almost 3am.