Alexander Zverev is through to his first grand slam semi-final after rallying to a four-set win over former Australian Open champion Stan Wawrinka.
The 22-year-old German appeared nervous in his first set on Rod Laver Arena but used his big serve to build into the match to post a 1-6 6-3 6-4 6-2 victory.
Zverev, seeded seventh, had never previously made it past the fourth round at Melbourne Park.