Widely lauded as title favourites following their breakthrough victory against the Crusaders in Christchurch last week, the comedown was swift for the Blues.
Up against the Fijian Drua, the worst-performing Australian-based side with one win from nine matches this season, for the first time, the Blues will not be satisfied with their sharp decline.
Leon MacDonald broke Sir Graham Henry's 32-match record for most wins as Blues head coach but, this week, there were no jubilant fist pumps in the box during an unconvincing display.
Another poor turnout at Melbourne's AAMI Park witnessed the Drua rattle the Blues for large parts of this contest through notable physicality and individual brilliance.
The second half in particular belonged to the Drua as they controlled possession and consistently hammered away at the Blues without being able to break through often enough.
While the Blues notched their eighth win in succession for the first time since 1997 and added another bonus point to remain top of the table, the Drua had them under the pump.
MacDonald took the opportunity to rotate his squad by making nine changes which perhaps in part explains their clunky efforts.
Blues captain Dalton Papalii and All Blacks prop Ofa Tuungafasi were among those rested, while Finlay Christie's injury absence at halfback was telling.
After opening the scoring in the fifth minute through AJ Lam's first strike the Blues were guilty of expecting the points to flow easily. They pushed miracle offloads, lacked patience in the red zone and the basic flow of their game was often missing.
Roger Tuivasa-Sheck's quiet outing from second five-eighth, after returning to a starting role, was testament to the Drua's defensive efforts.
The Blues ran in five tries and led 21-10 at halftime but the Drua closed within eight points in the second half to apply serious pressure.
When Drua wing Onisi Ratave crashed over midway through the second spell, an improbable upset was not out of the question.
Rieko Ioane shone from centre and his intercept, combined with Lam's double, pushed the Blues out to a comfortable margin but this was not the performance of a ruthless team; something of a reality check for MacDonald's men.
Forced to defend and as frustration set in, discipline fast became an issue for the Blues with replacement prop Karl Tu'inukuafe copping a yellow card for repeated team infringements. While one man short, the Blues' usually dominant set piece capitulated.
The Blues claimed three first-half tries – Sam Darry scoring the best from a well-worked lineout switch move – but poor handling, forward passes and Beauden Barrett uncharacteristically kicking dead from a penalty underlined their lack of fluency.
The Drua came to play, finding success through the middle and on the edges where their short kicking game exploited space to create their sole first half try to rangy hooker Mesulame Dolokoto.
The Fijians were often prepared to have a crack from deep and throw audacious offloads in their 22 while their powerful ball carries will leave the Blues with plenty of sore bodies in the coming days.
A two-week Australian tour was expected to provide the Blues with the chance to continue their upward trend. They will instead be demanding immediate improvements before trekking to Perth next week.
Blues 35 (AJ Lam 2, Sam Darry, Marcel Renata, Rieko Ioane tries; Beauden Barrett 5 cons) Drua 18 (Mesulame Dolokoto, Onisi Ratave tries; Simione Kuruvoli con, 2 pens) HT: 21-10