After a cameo off the bench in the first Test, Itoje seized his chance to start in the second, notching a game-high 15 tackles...
The second rower goes into the series decider in Auckland with his ears still ringing from the chants of travelling supporters bellowing his name as they urged the Lions to a famous 24-21 victory in Wellington.
After a cameo off the bench in the first Test, Itoje seized his chance to start in the second, notching a game-high 15 tackles to help overcome the world champions.
He also relished the added responsibility of calling the lineout and produced a livewire performance that sparked both his team-mates and the Lions supporters.
"He was immense from start to finish and the feeling of invincibility a young tyro like the England lock brings to proceedings should not be under-estimated," former Lions coach Clive Woodward declared after the match.
"It wouldn't occur to him for a second that New Zealand were unbeatable. He doesn't really understand the concept of defeat, long may that last."
Perhaps more telling than praise from northern hemisphere pundits was criticism in New Zealand media about Itoje's "cynical" repeated offside infringements as the match hung in the balance.
Itoje conceded two penalties but cost the All Blacks try-scoring opportunities, said local commentators, who have long championed the notion that rugby's best players operate on the edge of the law.
Itoje, 22, was not even born the last time the Lions scored a Test victory over the All Blacks in 1993. His father Efe was only three when the tourists won their one and only Test series in 1971.
As the youngest player in the tour group, Itoje was given the task of looking after its mascot, a cuddly toy lion named BIL, which he dutifully carried around when they were formally welcomed to New Zealand in late May.
Yet the rising star was hardly unknown before the Lions arrived.
He helped Saracens to last year's European Champions Cup and formed part of the England team that this year equalled the All Blacks' record of 18 straight Test wins.
The Irish Times in its pre-tour rundown described Itoje as "the youngest but most important Lion".
"There is a growing suspicion this freak athlete is actually a cyborg assassin sent back from 2029 to alter the All Black monopoly of rugby union," it enthused.
Now that Itoje has shown what he can do, the hype has reached even greater heights.
But the 1.95 metre (six foot five inch), 117 kilogram (18st 5lb) lock is keeping his feet firmly on the ground.
He acknowledged the chants of "Oh, Maro Itoje" belted out to the tune of the White Stripes' "Seven Nation Army", which drowned out the home support in Wellington.
Even his fellow lock Alun Wyn Jones was joining in the chorus as they left the field, though Itoje said his thoughts were already turning to the next Test.
"I did hear them," he said. "Obviously it's nice but I was fully concentrated on the game at the time so I can only really enjoy it now."
"I'm very honoured to be a part of this team. We've achieved something pretty good. But it's only half-time. It's 1-1."
Lions prop Jamie George said his England and Saracens team-mate, who is studying for a degree in African politics, was uncomfortable with the rock-star treatment.
"I actually don't think he does like it if I'm honest," George revealed.
Assistant coach Graham Rowntree was confident Itoje would again give his all in Saturday's winner-takes-all showdown and enjoy a stellar international career.
"He's continually striving to get better, asking everyone, 'How can I get better?' He'll go a long way," Rowntree said.