Tonga ended on a winning note in Viña del Mar after beating Zimbabwe 19-14 in the playoff for fifth place, have earlier come from behind to defeat Uganda by the same scoreline.
Meanwhile PNG finished in a share of seventh place, having lost 26-19 to Zimbabwe in the previous round.
Both teams were knocked out of title contention in the quarter finals, with PNG outclassed 29-0 by Germany and Tonga overwhelmed 28-7 by host's Chile in the first knockout round.
