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.

At the age of 19, Learner Tien defeated Daniil Medvedev in a five-set thriller that finished just before 3 a.m. in Melbourne.

The outcome was eyebrow-raising because of the wide gulf in experience and accomplishments between the two players at Margaret Court Arena.

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 became the first qualifier to claim an ATP top-five win at the Australian Open since Guillermo Garcia Lopez, who defeated Carlos Moya in 2005

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.

Learner Tien, a 19-year-old qualifier from California, became the youngest American man to reach the Australian Open's third round since Pete Sampras in 1990, upsetting a racket-tossing Daniil Medvedev 6-3,

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.

Inspired American teenager Learner Tien outlasted three-times Australian Open runner-up Daniil Medvedev to reach the third round with a 6-3 7-6(4) 6-7(8) 1-6 7-6(7) victory in a late-night epic on Thursday.