Brisbane Roar's hopes of progressing to the AFC Champions League round of 16 took a major hit in a 3-1 loss away to Suwon Bluewings on Wednesday.
A flurry of goals from Kwon Chang-Hoon, Seo Jung-Jin and Yeom Ki-Hun early in the second half at the Suwon World Cup Stadium sealed the away team's fate, with Luke DeVere netting a consolation in the closing stages.
The result leaves the A-League title-holders third in Group G, three points behind their South Korean conquerors and six points back from leaders Beijing Guoan, who drew 1-1 away to bottom side Urawa Reds.
A cagey first half, in which Suwon were largely content to allow Brisbane possession and sought to hit the visitors on the break, produced only a handful of genuine chances.
The first, from Yeom Ki-Hun's free-kick in the 18th minute, fell to Seo Jung-Jin but he saw a goal-bound header saved by Jamie Young.
With two minutes remaining in the half, the goalkeeper almost played his team into serious trouble when a misplaced clearance went straight to Lee Sang-Ho, who took one touch too many and failed to score from close range.
The Roar's only effort of note in the opening 45 minutes was supplied by the unlikely figure of Corey Brown, the fullback lashing a fierce shot wide of the post after picking up a deep corner unmarked on the edge of the area.
Suwon coach Seo Jung-Won introduced Kwon at half-time and was rewarded for the bold change by his team scoring the opening goal six minutes later.
A misplaced pass from Brown was collected by Jong Tae-Se, who laid the ball off to the new arrival. Kwon advanced into the area and beat the left-back before slotting a good finish across Young and into the far side netting.
Brandon Borrello should have equalised for the Roar barely a minute later, firing wide of the near post after running on to Andrija Kaluderovic's knockdown.
The visitors were left to rue that missed opportunity when the Bluewings doubled their lead in the 59th minute.
Lee Sang-Ho found Seo Jung-Jin in plenty of space inside the area and the 25-year-old cut back inside to send the unfortunate Brown the wrong way, leaving the three-cap South Korea international free to slot a cool finish past Young at the goalkeeper's near post.
Things went from bad to worse for Frans Thijssen's men six minutes later, when Yeom curled a magnificent free-kick into the top corner of the net, beyond the reach of Young's despairing dive.
Brown committed the foul that led to the third goal and received a yellow card for his trouble, as a night to forget descended into a nightmare outing for the young defender.
Brisbane did manage to pull one back through former K-League defender DeVere, who headed home Thomas Broich's curling free-kick unmarked in the 76th minute. But there was never any chance of a comeback for the Australian champions, who were thoroughly outclassed by the two-time AFC Champions League winners.
The Roar, who now face a tough match away to Beijing Guoan on April 21, are away to Adelaide United in the A-League on Saturday night.