Blues second-five Peter Saili scored after the final hooter to give his side a 40-36 victory over the Waratahs in their Super 15 trial game at Whangarei.
Leading 12-7 at halftime, the home side fell behind after the break, as Aussie winger Tom Ashton ran in three tries and league/AFL convert Israel Falou came off the bench to stamp his class on the encounter.
But down by 12 points, Sir John Kirwan's young side came storming back down the stretch and snatched the honours with Saili's late touchdown, his second of the encounter.
Blues 40 (Peter Saili 2, Lolai Visinia, Tim Perry, Waisake Naholo, Malakai Fekkitoa tries; Albert Mikoro conversion, Baden Kerr four conversions) Waratahs 36 (Tom Kingston 3, Cam Crawford, Jed Holloway, Israel Falou tries; Brendan McKibbon, Bernard Foley conversions); HT: 12-7
Meanwhile, the Hurricanes overcame an early 19-point deficit to overhaul the Rebels 47-45 at Geelong.
The Rebels opened the scoring within four minutes with a try to
centre Rory Sidey.
Running with the aid of the breeze, the home team had extended their lead to 19-0 within 14 minutes, following further tries to new skipper Gareth Delve and former Canes hooker Ged Robinson.
Lock James Broadhurst put the Hurricanes on the board with his team's first try in the 22nd minute and the visitors shaded the remainder of the opening half to only trail 28-33 at the break.
Wallaby James O'Connor did not reappear for the second half, after being sent to the bloodbin with a cut that required 18 stitches to his mouth and lower lip, although there was no suggestion of foul play.