Jan-Hendrik' Heymans unleashed an 80.50m effort with his final throw o add more than three metres to the personal best he held before arriving in Oregon.

South Africa's Jan-Hendrik Heymans claimed javelin gold in the early hours of Saturday morning (SA time) at the World Athletics U20 Championships in Eugene, Oregon.

The 19-year-old arrived as the event favourite and lived up to his billing in emphatic fashion, saving his biggest throw for last as he launched the spear 80.50m to seal the world title.

Heymans had already established his authority in the competition with a 76.92m opening throw before improving to a personal best of 79.42m in the fifth round. But there was more to come.

With his final attempt, Heymans unleashed an 80.50m effort to add more than three metres to the personal best he held before arriving in Oregon and establish a new World U20-leading mark.