The Blues have extended the horror run of archrivals and defending Super Rugby Pacific champion Crusaders, inflicting their fifth and biggest defeat of their latest campaign, 26-6 at Auckland's Eden Park.
The result extends the visitors' already record worst start to a season and represents the Blues' second win over their rivals in the last 20 meetings.
It's been 10 years since they last beat the Crusaders on home turf.
With rain pelting down, first-five Stephen Perofeta put the Blues ahead with an early penalty.
The visitors tried to keep the ball in hand and captain David Havili went close to scoring in the midst of a lineout maul. When the home side lost flanker Dalton Papali'i to a yellow card, they had another crack, but No.8 Cullen Grace knocked on near the tryline.
Eventually, as Papali'i's absence ended, they took the points on offer, with first-five Riley Hohepa successful from close range.
At the other end, Blues hooker Ricky Riccitelli also charged over from a lineout maul, but replays revealed he lost the ball, while forcing it. They feasted on a malfunctioning Crusaders lineout, stealing possession at will.
After half an hour, with conditions making handling difficult, Perofeta restored the Blues lead with a 40-metres penalty kick, but Hohepa responded from a similar distance.
The Blues suffered a major blow before halftime, when fullback Zarn Sullivan pinged a calf and hobbled off, but when Crusaders halfback Willi Heinz was yellow-carded after the siren, Perofeta put his side ahead again at the break.
Immediately after the restart, Cole Forbes - who replaced Sullivan - and Perofeta broke upfield and into the Crusaders 22, and after 13 phases, prop Ofa Tu'ungafasi barged over for the first try of the contest.
Within seconds, the Blues took a quick tap and poured back into Crusaders territory, with Forbes putting cetre AJ Lam across for a second. Havili hobbled off for the Crusaders, adding to their growing casualty list.
They were now cutting the shorthanded Crusaders defence to shreds. When winger Caleb Clarke burst out of his own half, they were quickly under another penalty advantage and winger Sevu Reece was yellow-carded for offside, as Heinz returned.
Under another penalty advantage and another yellow card looming, the Blues were lining up to score another try and Heinz was subbed, as he flirted with red.
Riccitelli was held up at a lineout maul, but the defence forced a turnover. The hosts continued to exert pressure and their pack simply marched through a Crusaders scrum to win another penalty, slotted by Perofeta.
From the kickoff, loose forward Corey Kellow charged down a Blues clearance and centre Levi Aumua seemed to have a try, but replays showed Clark knocking the ball free in a despairing goal-line tackle.
The Crusaders still had field position, but their lineout let them down again and Forces was able to clear the threat.
The result provided a fitting celebration of 100 appearances for Blues captain and lock Patrick Tuipulotu, who played out the entire 80 minutes in his comeback from a broken jaw.
There was no such celebration for counterpart Havili.
"Too many knockons, we couldn't build any pressure and a settled team like the Blues make you pay for it," he reflected. "They did that later in the second half.
"We've having those tough conversations, but we need to apply that on the field. We're not doing that at the moment, the effort's there, but those big moments we can't really execute at the moment and that's costing us."
The Crusaders must find an answer before they meet the Chiefs - who beat them in their season-opener - at Christchurch on Friday. The Blues return to Eden Park for an 'away' game against Moana Pasifika next Saturday.
Blues 26 (Tu'ungafasi & Lam tries; Perofeta 2 conversions & 4 penalties) Crusaders 6 (Hohepa 2 penalties)
