For the second time this season, the Crusaders have toppled the Blues after another Super Rugby Pacific arm-wrestle in Christchurch.
The reigning champions kept the visitors try-less, taking the spoils 15-3, with the visitors' cause not helped by the loss of captain Dalton Papali'i to a red card.
In front of a sellout crowd at Orangetheory Stadium, the pre-match intensity lived up to the hype, with neither side willing to budge.
While the Crusaders dominated all the early possession, the Blues held on to deny the keen hosts on several occasions deep inside their own half.
The match resembled the physicality of a test match, with both sides losing players to the medical card after heavy collisions.
Crusaders prop Joe Moody was the first to go with an ankle injury, before Blues lock Sam Darry suffered a suspected broken arm.
Despite all their dominance, the Crusaders struggled to turn it into points, with the Blues teetering the line of discipline perfectly, conceding five penalties inside the opening 20 minutes.
But the shackles finally did break after 30 minutes of waves of Crusaders' attacks, with lock Quinten Strange crashing over for the game's first try.
The intensity of the clash started to show, with both sides happy to clear their lines, as fatigue set in.
All Blacks first-fives Richie Mo'unga and Beauden Barrett exchanged penalties, as the Crusaders went into halftime with a 10-3 lead.
Poor kicks from promising field position stifled any potential Blues attack after the break, before the match-defining moment in the 44th minute.
Crusaders second-five David Havili fooled the defence with a terrific dummy pass, before setting winger Leicester Fainga'anuku free down the left wing.
With nobody ahead of him and cover defence closing in, he made no mistake with an acrobatic dive in the corner to extend the lead.
But it was the incident in the lead-up that turned the game on its head, with Papali'i cited for a high tackle.
The Blues captain collected Mo'unga's head with his shoulder, before he was shown a yellow card by the referee.
But only five minutes later, the Blues were informed it had since been upgraded to a red, and his match was over.
Despite the overwhelming odds, the Blues battled hard, and kept the Crusaders scoreless from then on.
However, they couldn't find the breakthrough that was needed, with Barrett looking the most likely to inspire a try.
Instead, the Crusaders' red wall proved too much to penetrate, as the defending champions made it two-from-two against the Blues this season, and even further bragging rights for soon-to-be All Blacks coach Scott Robertson over opposite Leon MacDonald.
Crusaders 15 (Strange, Fainga'anuku tries; Mo'unga 1 con, 1 pen) Blues 3 (Barrett 1 pen)
