Loose forward Luatua was sent off for a high tackle on Chiefs' winger Tim Nanai-Williams, whose side then used the resulting penalty to set up an attacking lineout that allowed hooker Hika Elliot to crash over from a rolling maul.
Elliot's try extended the score to 22-9 at the break, though until that point the game had been in the balance with first-five Ihaia West slotting three penalties and missing two.
