Kim Jin-su's extra-time header took South Korea past a stubborn Bahrain and into the quarterfinals of the Asian Cup on Tuesday as Paulo Bento's side sealed a 2-1 win at Dubai's Rashid Stadium.
The goal, scored in stoppage time of the first period of extra time, earned Korea a barely-deserved win after Bahrain's Mohamed Al Romaihi had earlier cancelled out Hwang Hee-chan's opener to take the game beyond 90 minutes.
Bento's side will now face either Qatar or Iraq in the last eight as the Koreans seek to win the title for the first time since 1960.
"The performance today maybe wasn't so good as it was in the previous games," said Bento.
"What happened was that we made a lot of easy mistakes, easy connections, easy passes and we lost the ball easily.
"Without the pressure of the opponent, the game became worse for us and easy for the opponents.
"We should be more effective in the way that we make our build up."
Victory came despite Korea making a slow start and Miroslav Soukup's Bahrain looked the more likely to break the deadlock.
Mohamed Marhoon's strike from distance flashed just wide of Kim Seung-gyu's goal with only four minutes on the clock and, midway through the half, the Al Riffa midfielder skied his free kick from a similar distance over the bar.
Korea grew more assertive and scored the opening goal two minutes before halftime, with Tottenham Hotspur forward Son Heung-min heavily involved.
The 27-year-old's incisive ball found Lee Yong and, while his low cross was parried by Sayed Shubbar, the rebound fell to Hwang Hee-chan who made no mistake from eight yards out.
The Koreans continued to press in the opening exchanges of the second half, with Hwang Ui-jo's attempt blocked by Shubbar and Hwang In-beom shooting over from outside the area. Jung Woo-young then had his free kick deflected wide.
Soukup's team were never overawed and, with 20 minutes remaining, Jamal Rashed's curling effort looked destined for the back of the net, only for goalkeeper Kim Seung-gyu to steer the ball wide for a corner.
However, Bahrain were level seven minutes later with Al Romaihi scoring from close range after Hong Chul had slid in to keep out Mahdi Al Humaidan's initial goal-bound effort.
Hwang Ui-jo should have won it for Korea three minutes into stoppage time when Waleed Al Hayam's poor back pass was intercepted by the Gamba Osaka striker, but he slid his shot wide of Shubbar's goal.
Kim Jin-su's bullet header following Lee Yong's deep cross from the right eventually secured the win for Korea, who may have to improve if they are to end their 59-year wait for the title.
Qatar wrestled their way past Iraq into the quarterfinals of the Asian Cup on Tuesday when a stunning free kick from the son of a former Iraqi international gave them a 1-0 victory at Al Nahyan Stadium.
Bassam Al-Rawi, whose father Hisham played for Iraq in the 1990s, found the net in the 62nd minute to decide a scrappy contest in favour of the 2022 World Cup hosts and set up a date with South Korea across town at Zayed Sports City on Friday.
Iraq, the 2007 champions, gave their all but paid the price for failing to take their chances and departed the continental tournament before the quarter-final stage for the first time since 1972.
"I thought it was a great performance from both teams," said Qatar coach Felix Sanchez.
"I just congratulate the players for their performance against one of the best teams in the competition."
Because of the current political and economic rift between the United Arab Emirates and Qatar, Iraq were cheered on by a noisy majority of the 14,000 crowd in the boutique ground, with barely a handful supporting the Maroons.
Qatar, who scored 10 goals and conceded none in the group stage, made the brighter start and left back Abdelkarim Hassan hit the bar in the fourth minute.
That was pretty much the extent of their threat on goal until he had a shot deflected onto the post just before the break, though, as the Qataris were muscled out of the game in midfield.
Iraq fared little better at the other end with Mohanad Ali having their best chance of breaking the deadlock in the 23rd minute as the 2007 champions started to make some progress with the ball over the top of the Qatari defence.
The young striker raced through on goal but Saad Al Sheeb bravely dived at his feet, with the goalkeeper getting a boot to the face for his efforts.
A defensive error put Qatar winger Akram Afif through early in the second half but his touch woefully betrayed him, and the ball trickled harmlessly to Iraq keeper Jalal Hassan.
It was a foul on the dangerous Afif on the left-hand corner of the box that led to the breakthrough just after the hour mark, defender Bassam stepping up and curling the ball over the wall and into the bottom left-hand corner of the net.
The Qataris were charged with confidence by the goal and poured forward to pepper Hassan's goal with shots in the next 10 minutes before Iraq regained their grip on the midfield.
Iraq defender Ali Adnan went close to matching Bassam's effort from a free kick slightly further out in the 78th minute and twice Iraqi forwards flashed headers wide as they laid siege to the Qatar goal in the last few minutes.
But the Qataris held them out to register a fourth clean sheet in four matches at the tournament, almost outnumbering their small band of fans when they celebrated with them at the end.
"I think the game was equal," said Iraq coach Srecko Katanec. "We pushed, we pushed but we didn't score. The players gave everything. That's it.