Loose forward Murphy Taramai scored a late try on the hooter as the Blues secured a thrilling 38-35 Super Rugby success over the previously unbeaten Lions at Ellis Park on Saturday.
The victory was a first of the season for the Auckland side, while they also inflicted a first defeat on the Lions, who have contested the last two Super Rugby finals.
The home side led for most of the match as they scored tries through wings Sylvian Mahuza and Aphiwe Dyantyi, centre Rohan Janse van Rensburg, flyhalf Elton Jantjies and prop Dylan Smith.
But the Ioane brothers were immense for the Blues as centre Rieko (two) and number eight Akira scored tries, to go with efforts from loose-forward Jimmy Tupou and Taramai. The Lions are next in action at home to the Sunwolves of Japan next Saturday, while the Blues travel to Cape Town to meet the Stormers on the same day.
The Lions hit the front inside two minutes when they took a quick penalty and scrumhalf Ross Cronje's long pass out to Mahuza saw the wing go over for the try.
The Blues twice turned down kickable penalties to search for attacking lineouts instead, but coughed up possession on both occasions.
The visitors were further punished for an error when an intercept sets Jantjies away and he frees Van Rensburg to score.
The Lions managed a third try in the first half two minutes before the break as Van Rensburg was held just short of the line but Jantjies eventually crossed over.
There was still time for the Blues to cross for their first score as a handling error from the Lions saw Akira Ioane race clear to dot down as the home side led 21-10 at the break.
The mistakes continued in the second half as Dyantyi stole another intercept and his electric pace gave the retreating Blues defence no chance as he raced clear for a fourth try of the season to extend the home advantage to 18 points.
It was the Blues who scored next though to stay in the contest when a period of pressure on the Lions line saw the ball popped wide to Rieko Ioane and he just had to fall over the line to score.
And the deficit was reduced to only four points when Rieko Ioane raced through a gap to score his second try of the night and set up a tense finish for the home side.
But the game swung again when the Blues tried to take a quick attacking line-out but were penalised for holding onto the ball on the ground.
The Lions kicked the penalty for an attacking line-out of their own and after hooker Malcolm Marx took them close from a driving maul, the ball was popped to Smith to barge over the line.
Amazingly, the Blues were not finished as they took the ball through the phases and Tupou powered his way over.
The Lions missed a chance to seal the game seconds later when Dyantyi chased a charge down, but knocked the ball on as he tried to ground it over the line.
And he was made to pay for that error as the Blues took the ball up field and after driving close, Taramai barged his way over the line.