Leading 13-0 at half-time, the Crusaders never allowed the Blues within striking distance in the second half, denying the home side any real chance of coming back into the contest.
The Crusaders were the first to create scoring opportunities, with two close calls in the Blues' right hand corner.
Richie Mo'unga opened the scoring for the visitors with a tidy drop goal while the referee played a penalty advantage.
Handling errors from both sides ensued, as a combination of weather and final nerves made for scrappy rugby.