Ihaia West's spectacular try five minutes from time handed the British and Irish Lions another stark warning of the challenge that lies ahead on their tour of New Zealand, as they were beaten 22-16 by the Blues in Auckland on Wednesday.
Having produced a nervy 13-7 victory over the Provincial Barbarians in their opener at the weekend, the Lions needed a win over the bottom club in Super Rugby's New Zealand Conference to ease any pressure that may begin to build.
Warren Gatland's men trailed at the interval despite an improved first-half display - a CJ Stander try sandwiched between scores for the excellent Rieko Ioane and Sonny Bill Williams - but failed to muster much of a response after the break.
A Liam Williams yellow card hampered their chances of recovery and, while Leigh Halfpenny managed to kick the Lions back in front, West's touchdown was a worthy match winner.
The result puts pressure on the Lions' trip to face the Crusaders on Saturday, and Warren Gatland could now face tougher questions than the one to which he took umbrage earlier this week.
It was the Lions who applied the early pressure and Jared Payne was unfortunate not to open the scoring when, after punting a loose pass forward, he lost a race with the ball for the dead ball line.
The Blues soon had their visitors stretched and a wonderful looping pass from Augustine Pulu released Ioane down the left to send the home side in front.
Stephen Perofeta, on his maiden Blues start, was wayward from the tee but was on hand to deny Payne a try at the other end soon after - the Ireland centre's boot deemed to be in touch as he dived for the line.
In contrast to the boos and heckles that greeted every Lions decision to take the three points in Whangarei at the weekend, the tourists were cheered for their ambition when opting to kick for the corner at Eden Park.
And that bravery was rewarded when Stander touched down from the back of a powerful maul, with Halfpenny adding the extras before sending over a penalty to put the Lions 10-5 in front.
Ioane had a second try chalked off for offside, while a head injury to Dan Biggar allowed Jonathan Sexton a chance to improve on his below-par display against the Barbarians.
As the heavens opened, a high tackle by Stander on Steven Luatua gave Perofeta the chance to close the Blues within two.
The fly-half's kick bounced back off the posts but Williams pounced on the loose ball after Jack Nowell had pushed it back over his own try line, sending the Blues in at half-time with a 12-10 lead.
Ioane went over again shortly after the interval but, like Payne in the same corner earlier in the match, was shown to have had a foot dragged into touch when the decision went to the TMO.
West - on for Perofeta - split the posts for the first points of the second half and the Lions were dealt a further blow when replacement Liam Williams was sin binned for challenging Matt Duffie in the air twice in quick succession.
Williams returned to the action with the Lions having reduced the deficit to two thanks to a Halfpenny penalty, before the full-back edged the tourists in front with another kick from distance.
But the joy was short-lived as, after a couple of fantastic offloads, West carved a route through the Lions defence to surge clear and cross under the posts, giving himself a simple conversion.
The Lions wasted a late lineout as the clock struck 80, sparking wild celebrations among the Blues players.