Sexton, scourge of England nine weeks ago when he orchestrated their Grand Slam downfall in Dublin, returned to haunt Northampton's red rose stars like Chris Ashton, Ben Foden and Dylan Hartley.
His 28-point haul - two short of equalling Diego Dominguez's Heineken Cup final record for Stade Francais against Leicester in 2001 - inspired Leinster to their second European title.
Sexton's Millennium Stadium masterclass - on and off the pitch - proved one of the long-running tournament's most inspired individual contributions.
Not only did the 25-year-old pick Leinster up by the bootlaces from 16 points down at half-time with two tries, four penalties and three conversions, but he also delivered a stirring dressing room rallying cry when his team-mates needed it most.
Sexton evoked the memory of Liverpool's astounding fightback against 2005 Champions' League final opponents AC Milan in Istanbul, when they wiped out a 3-0 deficit to lift the trophy.
"Besides what he produced in the second-half, some of his words at half-time really struck a chord with a lot of people," said O'Driscoll, of his Leinster and Ireland colleague.
"He mentioned about making it all the more memorable because of what we had to do from 22-6 behind. You could see he had the bit between his teeth and he was ready for it.
"To pick up two tries, produce a great kicking performance and just control the way he did, it was a phenomenal second-half performance by him.
"He really stood up to the plate. You need your 10 to be a senior player and a leader, and he was very much that for us. He was a man possessed."
Sexton kicked a match-winning penalty when Leinster lifted the Heineken Cup at Leicester's expense in Edinburgh two years ago, and once again he came up trumps, orchestrating a 33-22 victory that appeared inconceivable midway through a pulsating contest.
"I watch a lot of sport, and that Liverpool game just stuck in my mind for some reason," he said.
"I said that we see in sport that teams can come back like Liverpool did a few years ago. Stuff like this happens.
"It felt it was gone when they got that third try, that everything we had done to get out of the pool and get to the final was down the drain.
"We were shellshocked and we needed half-time. We regrouped. We had to believe, and we took our chances. We did everything in the first half that we said we weren't going to do.
"But when a team gets a score and gets the momentum going it is hard to stop. It was like a snowball effect."
Lock Nathan Hines' try sealed an epic win, leaving Northampton to rue a season without silverware despite reaching the Heineken final and Aviva Premiership semi-finals. First-half touchdowns for Foden, Hartley and flanker Phil Dowson proved insufficient.
O'Driscoll added: "We knew there were scores in us, and 27 unanswered second-half points proved that, although I don't think anyone was thinking that far ahead.
"It was about emotion, desire, and then application of your skills and the intensity you bring to the game. The difference between the two halves was absolutely huge.
"I think it makes the magnitude of it (the comeback) so much bigger because it is a Heineken Cup final. That is what makes it so much sweeter.
"The second one is meant to be the harder to win, and it's been a hard road beating a lot of the sides we have beaten along the way.
"Sixteen points down at half-time, to be able to come back from that answers a lot of questions about character and about the ability of the team.
"I think once we got the second try, we felt there was only going to be one winner. We had momentum and impetus, and they were sitting off us. We just had to continue playing.
"Once you go into a lead sometimes you can go into your shell, but I don't think at any stage we did that. We continued trying to get scores.
"This is very much up there, especially given the difficulty of the opposition we faced to get to the final.
"Both Aviva Premiership finalists (Leicester and Saracens) and three semi-finalists from the French league (Clermont Auvergne, Toulouse and Racing Metro) shows that."
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