Son Heung-min said South Korea had "more belief" than Iran as they safely reached the Asian Games quarter-finals, taking him a step closer to the gold that would spare him a career-threatening stint in military service.
Son captained the defending champions to a 2-0 win in a physical game in Cikarang, near Jakarta, to set up another daunting clash with a highly rated Uzbekistan side.
Nothing less than gold at the regional Olympics will be enough to exempt Tottenham Hotspur forward Son, 26, from his 21-month compulsory military service -- which could derail his career.
Son, the Asian record-holder for Premier League goals, admitted his side had felt the pressure of the last-16 knock-out tie, but said he was "very proud" of his team-mates.
"I think we were strong but Iran was also strong as a team," said Son. "It's important to be mentally strong. The pressure was there but I think we had more belief than Iran."
Japan-based striker Hwang Ui-jo opened the scoring in the 40th minute, calmly slotting in his fifth goal of the tournament from Hwang In-beom's cut-back cross.
The Gamba Osaka attacker is, like Son, a senior squad member facing his last chance to avoid military service.
Striker Lee Seong-woo, 20, doubled the scoring after 55 minutes, deftly collecting a botched looping clearance before firing home from just outside the box.
Lee denied that the threat of military service hanging over his older team-mates had added to the side's motivation.
"To tell the truth there was no special pressure over those kind of issues, because we are here to win this tournament," he said.
"And we only focus on this tournament and hope to reach the finals.
- 'Enjoy playing for my country' -
After a quiet start, the game sprang to life in the 19th minute as both sides hit the woodwork, with Iran's Mehdi Mehdikhani curling one shot onto the crossbar, before Hwang In-beom's response at the other end clattered off the post.
Chances continued to appear at both ends, with Iran not cowed by South Korea's stars.
Both sides committed players forward, with Iran's 17-year-old Younes Delfi -- linked with a move to PSV Eindhoven -- a lively presence.
South Korea's World Cup star goalkeeper Jo Hyeon-woo was forced off with an apparent injury just before the hour mark.
Son flashed a dangerous cross across the box, which Iran's keeper scrambled to deflect away with his fingertips.
But the tournament's star man had a quiet game overall, with his switch to the left flank in the second half failing to bear fruit.
Son is skipping Premier League action with Spurs to play at the Asian Games in Indonesia.
He scored the only goal in Monday's final group match against Kyrgyzstan to guarantee progress to knockouts.
"I have already said I feel very sorry (to miss Tottenham matches) but this tournament for me is very important because of my country," he said.
"I am enjoying playing for Spurs, enjoying playing for my country. Nothing is different. I play my best every time I take the field."
South Korea's class began to tell in an increasingly one-sided final period, as Iran were left to rue topping their preliminary group -- which ensured they played South Korea, who finished second after a shock loss to Malaysia.
South Korea's next opponents, Uzbekistan, who breezed past Hong Kong 3-0, have yet to concede in the tournament.