Up 19-5 at halftime, the Blues eventually fought off a spirited fightback from the home side to secure a 32-19 victory at Mt Smart Stadium on Tuesday night.
Moana Pasifika's third try midway through the second spell closed the gap to just five points with 20 minutes remaining.
But the Blues held their nerve, coming up with their fifth try of the match and a late penalty to seal the result.
The two teams were each playing the second match of a three-match run in eight or nine days, meaning both made wholesale changes from their previous game.