The Blues have overcome a scoreless second half to edge Western Force 22-18 at Perth, retaining the Super Rugby Pacific lead and extending their winning streak to nine games this season.
But the performance was their second scratchy showing of the competition's trans-Tasman crossover phase and missing a bonus point may yet see the lose their position atop the table this weekend.
"Credit to them, they came back and put us under pressure," said Blues captain Dalton Papalii. "We just held in there, but we put it on ourselves with our discipline and our errors.
"You can't win games like that - we've got to understand that and be better at executing in those moments."
After Bayley Keunzle put the home side ahead with a penalty - significantly, the Force's only successful goalkick of the night - the Blues were immediately under the pump, when lock Sam Darry was yellow-carded for offside, his team's third such infringement in the opening five minutes, as ref Angus Gardner lost his patience.
During Darry's absence, former Crusaders winger Manasa Mataele extended the Force advantage with a try, but Beauden Barrett had the Blues on the board with a penalty and soon after his return, Darry bullocked his way over to put his team ahead.
The visitors added two more tries before halftime - one to returning All Black flanker Akira Ioane and the other to winter AJ Lam from a slick offload by Roger Tuivasa-Sheck - and seemed to have the contest well under control at 22-8.
But the Blues were outscored 10-0 in the second half - former All Blacks lock Jeremy Thrush had a five-pointer for the Force - and had to survive a few nervous moments at the end, as the Force searched for another try for the massive upset.
After the final siren, they won a penalty in the Blues 22, took the lineout and forced 26 phases over an extra five minutes, before the Aucklanders finally stole the ball and found touch to survive.
The Blues host Melbourne Rebels on Friday, but will watch the Brumbies' encounter with the Hurricanes on Sunday, hoping the team from the NZ capital can topple the top Australian side.
Blues 22 (Darry, A Ioane, Lam tries, B Barrett 2 conversions & penalty) Force 18 (Mataele, Thrush & Abra tries, Kuenzle penalty)
