Liu Zhekai was the decisive winner of the boys' javelin with a personal best of 77.54m, becoming the first Chinese boy to win a world U18 title in the event.
Leading from round one, the Chinese thrower backed up his best with 76.96m, the second longest throw of the evening, and another solid attempt measured at 75.23m.
Johannes Schlebusch of South Africa took the silver with a last-round throw of 75.68m, and Song Qingshu made it two medals for China with 73.64m, also saving his best for the last round.
The competition started off well, with three boys throwing beyond the 70-metre line in round one. Liu was the early lead with 73.32m, ahead of Schlebusch's 72.31m, with the Polish world U18 leader Dawid Wegner in third with 70.56m.
The decisive moment came in round two. Liu sent the spear flying to 77.54m, which proved to be a distance none of his rivals could match on the day.
In round three, Schlebusch improved marginally to 72.61m, but otherwise, there was no change in the top positions for the majority of the final. It was only in the penultimate round that the competition was re-ignited.
First, Song Qingshu, down in fifth at that point, had an excellent throw of 70.64m to move into the medals, overtaking Wegner by just eight centimetres. Then Schlebusch improved his best to 74.00m, which in turn motivated the leader to get close to his best with 76.96m.
The order did not change in the final round, but that did not mean there was no excitement. The silver and bronze medallists both improved again. Song added exactly three metres to his best and Schlebusch threw a PB of 75.68m, moving to within two metres of the winner.
Liu ended the competition with a foul, but that took nothing away from the overall quality of his performance, or the winner's joy.