George North scored one of the great Lions tries as Australia were beaten 23-21 in Brisbane.
The 21-year-old, who moves to Saints this summer, burst from inside his own half before side-stepping Berrick Barnes and diving over the line.
North’s fellow Wales wing Alex Cuthbert also dotted down and Leigh Halfpenny added 13 points in a sound kicking display to secure the victory.
But the Lions were given a huge let-off at the end as Wallabies replacement Kurtley Beale missed two late penalties.
Australia had stayed in touch thanks to a brace of stunning tries from wing Israel Folau and five points from the boot of O’Connor as well as six from Beale.
But it was to be the goalkicking that let the home side down as O’Connor and Beale’s profligacy cost the Australians dear.
O’Connor set the tone early on, showing signs of nerves as he skewed two penalties wide of the posts early on.
But it didn’t take too long for the Wallabies to make up for those misses as genial scrum-half Will Genia broke from deep and put through a fine kick for Folau to score.
This time, O’Connor made no mistake and the home side were 7-0 to the good.
There was concern for the Lions on the injury front, too, as future Saint Alex Corbisiero, who had dominated in the scrum early on, received treatment on a calf problem.
But the prop was able to continue and slowly the men in red got into the game, Halfpenny reducing the deficient to four points with a penalty.
And the Lions soon had the lead as North’s moment of magic put them in front.
The wing burst through O’Connor’s attempted tackle, beat Berrick Barnes and held off the attentions of Genia to score a stunning try.
Halfpenny added the extras, before North saw another touch down in the corner ruled out by the TMO.
Halfpenny slotted a penalty soon after, though, as the tourists grabbed a 13-7 advantage with eight minutes to go before the break.
But in a see-saw encounter, the Wallabies bounced back with a corker of a try of their own from the fleet-footed Folau.
O’Connor continued his poor day with the boot, missing the conversion to keep his team a point behind.
Halfpenny also, unusually, missed a kick before half-time spurning a penalty chance, which had been earned after Corbisiero made a fine break through the middle.
The Lions headed in at half-time with a 13-12 lead and they extended it eight minutes into the second period, Cuthbert storming through the Wallabies defence to score.
Halfpenny made it 20-12, but O’Connor replied with a quick penalty to narrow the gap to five.
With 20 minutes remaining, replacement Beale brought the Wallabies back to within two.
It was a spirited effort from the home side, who had lost three players, Christian Lealiifano, Barnes and Pat McCabe, to injury during the game.
Halfpenny again issued a retort with another penalty from out wide before Beale’s break resulted in a penalty, which the Rebels player landed.
The script was written for Beale to win it for the Wallabies as he lined up another tee kick with seven minutes to go but, with his nerves jangling, the utility back sent the ball right of the posts.
It was a huge reprieve for the Lions but they got an even bigger one a minute before the end as Beale slipped while taking a long-range penalty.
It completed his personal torture and handed the Lions a 1-0 series lead ahead of next Saturday’s second Test in Melbourne.