A first-half try from Peachey, followed by further efforts in the 60th and 76th minutes, gave Penrith the crucial edge in the ‘home’ game played in Christchurch, New Zealand.
The Warriors led 18-14 at half-time, but failed to score a second-half point as they fell to their sixth loss in 10 games this season.
Gusty conditions contributed to a scrappy contest, with crucial errors from both sides ensuring the game remained in the balance until the final minutes.