All Blacks wing Sevu Reece bagged a brace of tries for the visitors, who moved back to the top of the New Zealand Conference standings.
Reece was also yellow carded in the match for a professional foul.
The Crusaders were well below full strength due to injuries and resting players.
It could well be the Sunwolves' final Super Rugby match now that the season has been suspended due to the coronavirus and New Zealand travel restrictions and quarantine rules.