The Blues women have fired a 40-26 warning shot at archrivals Chiefs Manawa in the build-up to another meeting in the Super Rugby Aupiki final in two weeks.
Leading 28-7 with halftime approaching, the notherners allowed their unbeaten opponents to within a converted try in the dying moments of the encounter, but replacement prop Cheyenne Tuli-Fale ploughed over from a goal-line ruck to seal the Blues' first-ever win over their southern neighbours.
The result was also the Chiefs' first loss of the season and the race is now on for the right to host the final, with one round of regular season games remaining.
The two teams exchanged tries initially, but Blues hooker Grace Gago put the Blues ahead for good with their second try, sparking a 21-0 run that also included a penalty try, a yellow card to Chiefs fullback Renee Holmes and an intercept effort from centre Sylvia Brunt.
With the break approaching, the Chiefs clawed one back, as hooker Luka Connor rumbled over from an attacking lineout maul, closing to 28-14.
Blues captain Maia Roos was first to score after the restart, seemingly putting the contest out of reach for the home side, but tries to prop Krystal Murray and replacement Chelsea Semple put the Chiefs within reach, until Tui-Fale's clincher in the final seconds.
Chiefs Manawa won the inaugural women's crown two years ago, but were shocked by Matatū in last year's final - their first-ever defeat in the competition. This loss to the Blues is their second.
"First time beating the Chiefs, they're a quality side," reflected Roos. "They've been the dominant side in Aupiki for the last 3-4 years, so I'm really happy for our team.
"It took the whole squad... we played a selfless game and we're really happy with the result.
"We went hard on our set-piece this week - it's been a focus of ours to be the most dominant forward pack and we felt like we hadn't shown that yet, so that was our challenge to ourselves. Really proud of our forwards today."
Chiefs Manawa still hold a one-point lead atop the competition table and face champions Matatū next Saturday, while the Blues will chase that bonus-point win over Hurricanes Paoa.
Blues 40 (Itunu, Gago, Brunt, Roos & Tuli-Fale tries; penalty try; Cottrell 4 conversions) Chiefs Manawa 26 (Tui, Connor, Semple & Murray tries; Holmes 2 & Bayler conversions)
