Safawi Rasid fired a first-half brace as the Malaysia Under-23 stunned defending Asian Games champions South Korea 2-1 to top Group E and confirm their place in the last-16 on Friday.
Not even the introduction of Son Heung-min could inspire the Koreans, who failed to breakdown the resilient Malaysians despite dominating the lions share of possession.
Malaysia came into this game with a clear game plan, to sit back in numbers and press their opponents hard in the final third.
That strategy paid off after just five minutes, thanks to a huge stroke of good fortune.
Haziq Nadzli pumped a long ball upfront, and Safawi charged at it as Korea goalkeeper Song Bum-keun came to collect.
But the custodian also crashed into his defender, and the ball slipped from his grasp.
Credit to Safawi, who was alive in the box, lapped up that error to stroke home into an empty net and give the Malaysian a shock lead.
That howler jolted Korea into life, and they began to come at Malaysia with more intent.
Their best chance arrived after 35 minutes as Hwang Hee Chan was put through on goal, but Haziq was quick off his lines to deny the striker with his body.
Safawi then dealt Korea another blow just before half-time through a clinical counter-attack.
Syafiq Ahmad instigated the move by feeding the Johor Darul Ta’zim forward, who outmuscled Hwang Hyun-soo before poking past Song in off the post.
Korea needed to intensify the pressure in the second half, as they came out in search of an early goal to force the issue.
But again, Malaysia were tactically astute in their shape, putting almost every man behind the ball to absorb the defending champions’ pressure.
Hwang fired another shot harmlessly wide, and Totthenham Hotspur star Son was finally summoned from the bench on the hour mark to make a difference.
Son slotted into the playmaker role to feed the wingers, but Malaysia were not giving the Korean attackers any time or space in possession.
He was clearly frustrated with the lack of chances his side could fashion, and a shake of the head after a foul on Baddrol Bakhtiar told the story.
Hwang Ui-jo pulled a goal back for Korea three minutes from time, and it set the tone for a comeback.
Son had one final chance from a free-kick just outside the box, but he fired wide, and Malaysia hung on bravely to notch one of their biggest wins in recent history and book a spot in the knockout round.
For Son and team, a win against Kyrgyzstan should almost be a certainty.
But on the evidence of the night, anything can happen.
Haziq Nadzli (GK), Dominic Tan, Adam Nor Azlin, Irfan Zakaria, Rizal Ghazali, Syazwan Andik , Baddrol Bakhtiar (C), Syahmi Safari, Akhyar Rashid, Syafiq Ahmad, Safawi Rasid
Song Bum-keun (GK), Hwang Hyun-soo, Kim Min-jae (C), Kim Jinya, Lee Jinhyun, Hwang Hee Chan, Lee Siyoung, Cho Yumin, Hwang Ui Jo, Kim Geonung, Kim Jung-min
Photo Credit: FAM