THE late injection of three Queensland Reds players wasn't enough as Australia lost to New Zealand to miss out on the World Rugby under-20 championship semi-finals.

The Junior Wallabies were surprisingly dominant up front but weren't clinical enough as they crashed to  a 27-18 defeat at the tournament being played in France.

Reds trio Harry Hockings, Hamish Stewart and Jordan Petaia were cleared to join the age-group side as injury cover this week.

They made an impact, with lock Hockings part of a powerful set piece effort and Stewart an astute general in slippery conditions at five-eighth.

Trailing 17-15 at halftime and 20-18 entering the final quarter, they slipped up late as New Zealand sevens star Vilimoni Koroi created a try to Jamie Spowart.

Stewart set up Australia's first try to flanker Fraser McReight and their second was a penalty try following a series of dominant scrums.

Australia will now contest the fifth-to-eighth classification for a seventh successive time at the tournament.

Their next opponents are Wales, who they lost to 26-21 in their opening match.

The semi-finals are identical to last year, with New Zealand facing France and England against South Africa.