Sonny Bill Williams' red card proved to be costly as the British and Irish Lions produced a storming fightback to end New Zealand's 47-match winning run on home soil and level the series with a famous 24-21 victory in Wellington.
Williams was dismissed by referee Jerome Garces after only 25 minutes for a shoulder charge on Anthony Watson in the driving rain at a raucous Westpac Stadium on Saturday, becoming the first All Black in 50 years to be sent off.
Beauden Barrett booted seven penalties - as well as missing three - to ensure the world champions led for much of a pulsating second Test, but the Lions came roaring back with tries from Taulupe Faletau and Conor Murray in the final 20 minutes.
And Owen Farrell's penalty three minutes from time consigned New Zealand, who led by seven points with just 12 minutes to play, to their first loss on home soil since 2009 and kept the Lions in the hunt for a first series win over the All Blacks for 46 years.
The composed Farrell scored 14 points with the boot as Warren Gatland's men showed great character to set up a decider at Eden Park next weekend.
The Lions made a confident start, putting together some slick passing moves as they asked early questions of the All Blacks defence, and they breathed a sigh of relief when Barrett's first penalty struck an upright.
Barrett made no mistake from the tee 19 minutes in after the fired-up All Blacks pack won another penalty when a scrum went down, but Farrell levelled with a superb long-range strike.
Moments later the game turned in the Lions' favour when centre Williams was given his marching orders by Garces for taking out Watson with his shoulder.
Jack Nowell replaced Watson, while Ngani Laumape came on for his debut in place of Jerome Kaino in an All Blacks reshuffle as the rain continued to hammer down.
Watson returned after passing a head injury assessment before Barrett restored New Zealand's advantage after Murray was penalised for not rolling away, but great work from Maro Itoje and Liam Williams enabled Farrell to level again.
Farrell made it three from three right on the stroke of half-time to make it 9-9 after Barrett had edged the All Blacks in front once more.
Barrett was off target with two penalties, but also landed a couple to put the All Blacks six points in front as the Lions paid the price for failing to keep their discipline early in the second period.
Mako Vunipola was sent to the sin bin for illegally cleaning out the influential Barrett, whose sixth penalty of the night in easing conditions extended the world champions' lead.
The Lions had offered nothing going forward, but came up with the opening try just after the hour-mark despite also being down to 14 men when Faletau ploughed his way through Israel Dagg to finish in the corner after the ball was worked swiftly from right to left.
Barrett slotted home another penalty as the tension mounted, yet the Lions hit back again when Murray got quick ball and darted through a gap to go over following a great break from Jamie George.
Farrell added the extras to level a gripping contest 10 minutes from time and after Kyle Sinckler was taken out in the air, held his nerve to complete the comeback with time running out, sparking huge celebrations from the tourists.