Great Britain Under-18s were beaten 3-2 by the number-one seed in the group Korea U18s at the World Championship Division 2 Group A in Gangneung.
Despite taking the lead and having a number of good chances, especially in the second period, GB could only beat Lee Jungmin twice as he turned away 28 shots.
GB went ahead on the powerplay as Liam Kirk’s shot was saved and Jordan Buesa batted in the rebound for his first goal of the tournament (5:55).
Korea improved as the period went on and Ethan James produced a great glove save to deny Kim Geon Woo, before Park Gangeun broke free on the blueline and fired top shelf (13:37).
Joshua Waller hits the pipes as GB went close in the opening stages of the second period, before the hosts had a goal ruled out for a man in the crease.
Korea went ahead when Kim Minje broke into the offensive zone and fired high past James (36:11), while they had another goal washed out for man in the crease.
The hosts made it three when Jin Geonho got the final touch following a scramble in front of the net (44:05).
Tyler Cooper closed the gap on a five-on-three powerplay as he ghosted in at the backdoor to score his third goal of the tournament (56:52).
GB lifted James for the extra skater but could not find the equaliser.
Head coach, Martin Grubb, said: “The terminology we are using is we are happy but not satisfied.
“I was proud of the boys. I thought we battled hard and it is fine margins.
“We made a couple of mistakes and gave up goals. At this international hockey level, if you give up chances then they are going to punish you.
“Our penalty kill was huge but we just couldn’t find the bounces or get that goal at the end.”
GB U18s return to action tomorrow (Wednesday) against Lithuania at 4:30pm local time, which is 8:30am in the UK.