This rollercoaster of a victory over the old enemy has eased the pressure on the Blues - and broken a seven-game losing streak stretching back to May last year. It it will also cause a fair bit of soul-searching in Christchurch.
It was a bizarre game for many reasons - the way the Blues took so long to get into it, and once they did how the Crusaders imploded, barely able to string a pass together as Sir John Kirwan's men poured on an incredible 29 unanswered points.
In the middle of it all, 20-year-old first-five Simon Hickey went serenely about his work. He kicked six from seven shots at goal and looked assured.
The Blues leave for South Africa today and their two matches against the Bulls and Lions in good spirits, the Crusaders on the other hand must be wondering where to start. They are yet to earn a competition point.
Their composure deserted them entirely, they fumbled, missed tackles; frankly they looked in disarray. In their loss to the Chiefs last weekend their skills let them down in the end but they showed grit. There was determination again last night, but there was a lack of clear thinking. They are in a deep hole.
In scoring four tries for a bonus point, Blues showed just how dangerous they will be this season if they can play with confidence. They have the personnel - Frank Halai, George Moala and Charles Piutau are a handful for any defence. Returning former All Black Jerome Kaino, watching from the stand, will add to their firepower once he becomes available after their African adventure.
On this evidence, it's hard to know what to expect of the Blues in the Republic because after 34 minutes it looked like it would only a matter of how many the Crusaders won by. Tries from hooker Corey Flynn and fullback Colin Slade helped push the score out to 17-3, the Blues offering little in response.
It was a moment of magic from Frank Halai which turned the Blues' fortunes around. On the counter, the ball was shifted quickly to where Halai was lurking and he showed the pace and right foot step which earned him an All Blacks selection last year.
There was more to come, and quickly. From the re-start, young lock Patrick Tuipulotu got a pass away under pressure to Tevita Li, who eluded the tackles of Colin Slade, Richie McCaw and Rob Thompson to score an extraordinary try.
Coach Kirwan was out of his seat well before halftime and with the score 17-15 it was no wonder.
The Crusaders were out warming up with passing drills well before the Blues emerged from halftime but worse was to come for them. A Moala try from a Reynold Lee-Lo and Slade defensive howler was followed by a try to Willison, who dived on a Piri Weepu grubber.
In the frantic final minutes, Steven Luatua was sinbinned and Crotty, running on to an Israel Dagg break, scored to narrow the gap for the Crusaders. Appropriately, Hickey had the last say with a penalty.
Blues 35 (Frank Halai, Tevita Li, George Moala, Jackson Willison tries; Simon Hickey 3 cons, 3 pens) Crusaders 24 (Corey Flynn, Colin Slade, Ryan Crotty tries; Tom Taylor 3 cons, pen) Halftime: Crusaders 17-15