Spurs made a slow start, which may have explained why Postecoglou was raging during the drinks break midway through the first half.
The livid Aussie was ordering his players to go “man to man” in the pressing, with microphones catching him dropping the F-bomb as dressed down his squad.
It had a positive effect though as Spurs then went on to score three goals before half-time.
Dejan Kulusevski, playing as a central striker, broke the deadlock, leaping onto the rebound from a saved Son shirt and smartly turning into the roof of the net.
Son then gave his 25,000-strong, adoring crowd what they wanted, as he cut in from the left and fired into far corner.
It was a typical strike from Spurs’ captain, and teed up by Jamie Donley, who impressed at inverted left-back again.
Son then made it three in stoppage time, playing a one-two with Kulusevski, nutmegging his defender and then firing into the far corner.
It was a strike which delighted Spurs fans on social media as they look forward to their captain’s tenth season at the club.
Commenting on the brilliant link-up between Son and Kulusevski, one fan said: “Really difficult to judge the standard we’re up against, but Son has been out of this world. I guess he’s giving the crowd something to remember.”Another described the wonderful strike as “filthy” while a third said: “Oh, that was incredibly lovely.”
Spurs beat a K League team 6-3 two years ago under Antonio Conte in a madcap game of chances – and that is what it proved to be again in the second half.
The Korean side brought on the division’s top scorer at the break, Stanislav Iljutcenko, and he fired a quick-fire double, both from close range, to make it 3-2 by 54 minutes.
Postecoglou’s men went back in front though as 19-year-old Will Lankshear, who has impressed throughout pre-season, turned home Timo Werner’s cross.
The goal frenzy was not over though as Oberdan made it 4-3 with a thumping volley.
There could have been more goals with James Maddison and Emerson Royal hitting the woodwork and the Korean side missing a number of good chances.Oliver Skipp was lucky to escape serious injury when caught on the knee by an awful tackle which would have been a red card in a competitive game .Spurs have won all five of the pre-season games so far – including the 7-2 win over Cambridge behind closed doors – and 21 goals in the process.