Northern Ireland came from behind to defeat South Korea 2-1 and inflict an early blow in the visitors' preparations for the World Cup finals.
Kwon Chang-hoon opened the scoring in the seventh minute for the Asian heavyweights, Northern Ireland equalising by forcing a Kim Min-jae own goal from a clever set-piece 13 minutes later.
South Korea, led by Tottenham star Son Heung-min and with Swansea City midfielder Ki Sung-yueng wearing the captain's armband, controlled possession and pressed in search of a second goal after the break.
But a succession of substitutions as the game wore on interrupted the flow of the contest and Northern Ireland, missing the likes of regular captain Steven Davis and centre-forward Kyle Lafferty due to injury and with highly rated young Norwich fullback Jamal Lewis making his debut, pounced to snatch victory through debutant Paul Smyth with four minutes remaining.
It was a gratifying and somewhat unexpected outcome for Northern Ireland boss Michael O'Neill, who in January rejected the advances of Scotland as they sought to appoint him as Gordon Strachan's replacement.
Next up for Korea is a friendly against fellow World Cup participants Poland in Chorzow on Tuesday, as they build toward matches against Sweden, Mexico and holders Germany at the finals in Russia.
Northern Ireland are not back in action until facing Panama in May.
The visitors took the lead early on, Park Joo-ho lifting a well-weighted pass over the Northern Ireland defence to release Kwon in on goal.
The Dijon forward produced a delicate first touch to bring the ball under control, before steering a confident finish past debutant Trevor Carson.
Jamie Ward had the ball in the back of the net in the 13th minute when he guided home the rebound from a Josh Magennis shot, but the effort was correctly ruled out for offside.
The hosts suffered a blow when they lost veteran defender Aaron Hughes to injury in the 18th minute, but they were level two minutes later, courtesy of a well-worked free-kick routine.
With South Korea braced for a shot on goal, George Saville instead played Ward into space down the right side of the area and the forward's low, firm pass across the face of goal was inadvertently turned home by Kim.
Magennis called Kim Seung-gyu into action with a dipping strike two minutes into the second half, while Carson was required to save from a deflected Park effort as the hour-mark approached.
Substitute Conor McLaughlin's important block denied Kim Shin-wook from close range with 10 minutes remaining in normal time.
And Northern Ireland snatched the victory when Conor Washington did well to hold the ball up and nod it into the path of Queens Park Rangers player Smyth, who took a touch before firing a low finish into the bottom corner just 194 seconds after coming off the bench.