It means the Highlanders are into the fifth-sixth playoff on Saturday against the New Zealand Barbarians, who beat the Fijian Drua 36-14.
Neither side covered themselves in glory in the first half yesterday — but they could hardly be blamed.
Conditions at Owen Delany Park were dreadful with the rain coming down sideways and the ball turning into a bar of soap.
There is something to be said for seeing young rugby players willing to chance their arms and try exuberant offloads, but it was not a day for flashy stuff, and the first 30 minutes were almost entirely about knock-ons and turnovers.
The Baby Landers turned down a simple penalty goal attempt and were made to pay right at the end of the first half.
Moana Pasifika openside Thomas Setitaia, a real talent, put through a grubber and, while it appeared reasonably clear he knocked on, he was awarded the try.
The weather improved and it was no coincidence the Highlanders took control when they had rising stars Dylan Pledger and Mika Muliaina off the bench and pulling the strings in the inside backs.
Moana Pasifika lost a man to the bin, but while Highlanders hooker Shaun Kempton swooped for the first of his two tries, Moana bit back straight away.
Then it was one-way traffic for 25 minutes.
Dominant lock Josh Tengblad, clearly on the fast track to being a big-boy Highlander next year, popped clean lineout ball to a charging Gregor Rutledge for a simple try; a nice Muliaina run led to Louis Lepionka darting over from close range; and a second Moana sin-binning was followed by winger Kyan Rangitutia barging through four defenders to the line.
Pledger capped another wonderful display with a runaway try, and Kempton grabbed a nice front-rower’s double in the final minutes.
The other influential player for the Baby Landers was midfielder Tayne Harvey, who showed a nice mix of strength and skill.
Blindside flanker Christian MacEwan was also vigorous in everything he did.
Super Rugby U20
The scores
Highlanders 40
Shaun Kempton 2, Gregor Rutledge, Louis Lepionka, Kyan Rangitutia, Dylan Pledger tries; Mika Muliaina 5 con
Moana Pasifika 12
Thomas Setitaia, Alan Talataina tries; Hohaia Whiu con
Halftime: Moana Pasifika 5-0.
