Son Heung-min's South Korea came back from the dead to beat Saudi Arabia 4-2 on penalties on Tuesday and join dark horses Uzbekistan in the Asian Cup quarter-finals.
South Korea will face Australia in the last eight while the Uzbeks play hosts and holders Qatar after beating Thailand 2-1.
Second-choice goalkeeper Jo Hyeon-woo was the hero for South Korea in Doha, saving penalties from Sami Al-Najei and Abdulrahman Ghareeb in the shootout.
Jo was only playing because of a serious knee injury to regular stopper Kim Seung-gyu in training earlier in the tournament.
After a nail-biting game ended 1-1, Hwang Hee-chan scored the decisive penalty for Jurgen Klinsmann's side, who are aiming to end a 64-year Asian Cup title drought for South Korea. Saudi coach Roberto Mancini disappeared down the tunnel before Hwang took the winning penalty.
"I think this win gives the team an enormous amount of energy," said Klinsmann, who faced fierce criticism in South Korea following draws with Jordan and Malaysia in the group phase.
"It gives the team even more spirit. This is a group of players that I really enjoy working with because they have a lot of heart."
His opposite number Mancini said he had not meant "to disrespect anyone" by leaving the pitch before the shootout had concluded.
"I apologise, I thought it was finished," the Italian said.