Asafo Aumua was the star performer for the young All Blacks as he scored a hat-trick to inspire his side to a dominant triumph at the Mikheil Meskhi Stadium in Tbilisi.

He became just the second player to notch a hat-trick in the final of the competition, while New Zealand also ran in a record-breaking 10 tries - the most ever scored in the tournament's showpiece contest.

New Zealand had effectively sealed victory by half-time as they led 40-7 at the break.

Dalton Papali'I, Pouri Rakete-Stones, Isaia Walker-Leawere and Luke Jacobson all went over in the first half, while Aumau scored twice and Stephen Perofeta contributed with 10 points.

Tries from Josh McKay, Aumua, Tom Christie and Jacobson after the restart completed the rout as New Zealand cruised to a commanding win.

The result handed New Zealand their sixth Under-20 Championship crown after they triumphed in 2008, 2009, 2010, 2011 and 2015.

"It's pretty exciting to be honest, it's not every day that you get to say that you're world champions," New Zealand coach Craig Philpott said.

"New Zealand have a proud history in this final as have England so we are really proud that we are going to be taking some silverware home."

South Africa claimed the bronze medal as they beat France 37-15, while Scotland took fifth place by edging Australia 24-17.

Wales' narrow 25-24 win over Italy saw them finish seventh and Ireland were ninth, ousting Georgia 24-18.

Samoa were relegated to the Under-20 trophy, the level below the World Championship, after they were beaten 53-42 by Argentina in a high-scoring affair.