A try in the final 10 minutes from home replacement Ihaia West, which he converted, broke the visitors’ hearts and proved to be the decisive moment of a tight encounter.
Two second-half penalties from Wales full-back Leigh Halfpenny, plus his conversion of a CJ Stander try, had put the Lions into a one-point lead, but they failed to hold on.
They weren’t helped by a yellow card for Liam Williams, who was sent to the bin just a few minutes after coming on, as West’s effort followed tries just before the break for Rieko Ioane and Sonny Bill Williams.
It leaves the Lions needing to regroup and quickly ahead of facing the Crusaders on Saturday.
After their scratchy 13-7 tour-opening victory over New Zealand Barbarians, the Lions looked much sharper in the first half, but still fell behind early on and trailed at the break
Ioane was the game’s first try-scorer, Charlie Faumuina’s pop pass finding fly-half Stephen Perofeta, who spread the ball wide. It was far from an easy finish, but the impressive Ioane hit the ball at pace, bypassing Jack Nowell to cross in the corner. Perofeta was unable to convert.
Jared Payne’s attempt to hit back for the Lions was then ruled out by a foot in touch, but their deficit seemed to spur Gatland’s men into action.
After turning down a series of kickable penalties – a decision applauded by the home crowd – the Lions were rewarded when a well-worked line-out move saw Stander driven over.
Halfpenny converted and then added a simple penalty following a powerful scrum surge and with Stander, Courtney Lawes and Rhys Webb impressing, things looked promising for the visitors.
It didn’t last. Referee Pascal Gauzere and TMO Marius Jonker were the centre of attention, Ioane rightly having a second try ruled out for Ofa Tu’ungafasi’s offside tackle on Dan Biggar.
The hit forced the Wales pivot off for a head injury assessment, Johnny Sexton his replacement, but there was still time for more drama before the break.
Perofeta’s penalty following a high tackle from Stander stuck a post, the rebound falling to All Blacks superstar Sonny Bill Williams who won the race to the ball to score.
Jonker decided the centre hadn’t knocked-on in the process, awarding the try, and Perefota’s fist kick of the day ensured his team led at half time.
An interval deficit was tough on the Lions, and only a superb cover tackle from Nowell stopped Ioane from scoring in the corner at the start of the second period.
With Biggar staying off the field, Sexton continued at fly-half, and a further change saw Wales back Liam Williams make his first Lions appearance, replacing the injured Payne.
Williams slotted in on the left wing with Elliot Daly moving to centre, but the Blues were dominant.
Replacement West slotted a penalty after Justin Tipuric was penalised for not rolling away to give the Blues a deserved five-point lead.
It prompted Gatland into changes, Peter O’Mahony, Joe Marler and Kyle Sinckler all introduced up front, but they mattered little as Liam Williams was then yellow carded.
The Wales international was sent to the bin for the second of two tackles in the air on Matt Duffie, leaving the Lions with a points and numerical disadvantage going into the final quarter.
Two quick Halfpenny penalties quickly put the Lions back ahead and it looked like they would hang on by the narrowest of margins.
But West, who had come on for Perefota, got himself on the end of a trademark Sonny Bill Williams offload and scythed his way to the line before adding the extras to his own score.
It sent the home crowd wild and left the Lions chasing the game and although they had a late chance to snaffle a match winning try, Rory Best’s line-out went to pot and the game was lost.
