A precious victory in this week of all weeks for John Kirwan and the Blues.
A defeat to the Waratahs at Eden Park tonight would have given the impression of a season in freefall following the Benji Marshall debacle.
The Blues, a franchise under the spotlight, haven't won an away match for well over a year, but their home record this season remains impeccable.
This was a quality Waratahs side too, one which pounded the Blues into mince meat in their pre-season match in Sydney. Kirwan was concerned about the physical challenge against a team with two giants in the form of Will Skelton and Kane Douglas, but the Blues shaded that, and, more remarkably, played smarter than the men from Sydney.
This was light years from their weak effort against the Hurricanes in Wellington last weekend.
Ma'a Nonu, who missed that defeat with a calf problem, was direct and aggressive and Jerome Kaino put in one of his most influential performances of the season. Try scorers Francis Saili and Lolagi Visinia were dangerous and in Frank Halai and Charles Piutau they had able assistants.
Weepu, back from his health scare, played most of the second half off the reserves bench.
The four competition points keeps the Blues in touch with the other New Zealand teams and edges them up towards the middle of the table in eighth. More than that, it allows them to re-callibrate after the Marshall mess. They will look forward to the Reds at Eden Park next Friday with renewed confidence.
The Waratahs would have left the field at halftime wondering how they weren't in the lead. They were playing the majority of the rugby, and with men like Kurtley Beale and Israel Folau in their side they had every right to look for an expansive game, but their ambition was their undoing at times. Final passes went to ground when players were in scoring opportunities, literally in the case of Bernard Foley, who had done so well to break through only to throw a shocking pass to his unmarked wing Cam Crawford.
The Blues' lineout was rattling - it was as if they didn't know where to throw it with Steven Luatua biding his time on the reserves bench - but somehow they won enough ball and made enough scrambling tackles to stay in front.
Visinia's try owed much to the directness of Nonu, who burst through the defence and featured later when throwing the long cut-out pass for Lolagi Visinia, and Saili capitalised on quick thinking from his teammates following a botched Bernard Foley kick.
They had a bit of luck - Rob Horne's effort in the second minute was ruled out for a double movement and he knocked on with a clear run to the line later in the half.
Folau, the Waratahs' main attacking threat this season, couldn't get going, with Nonu in particular testing his positional play with grubber kicks. A tactical win to go with their physical dominance. A precious victory indeed.
Blues 21 (Lolagi Visinia, Francis Saili tries; Simon Hickey 3 pens, con)
Waratahs 13 (Jacques Potgieter try; Bernard Foley 2 pens, con)