The Dubliners were trailing 22-6 at the interval but Sexton came to the fore and racked up 22 second-half points to bring his total haul to 28-points.
The tally took Sexton two short of Diego Dominguez's Heineken Cup final record for Stade Francais against Leicester Tigers in 2001.
But his second-half masterclass, which included two tries, three conversions and two penalties, inspired Leinster to a memorable cup triumph.
But it was not just on the pitch that Sexton had a major impact. The Ireland fly-half also delivered a stirring half-time rallying call.
Sexton evoked the memory of Liverpool's astounding fight-back against 2005 Champions' League final opponents AC Milan in Istanbul, when they overcame 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, a Lions tourist in 2001, 2005 and 2009.
"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."
While O'Driscoll has established himself as a Lions legend his provincial and national teammate, Sexton, is a front runner to make the 2013 tour to Australia.
"I watch a lot of sport, and that Liverpool game just stuck in my mind for some reason," added Sexton.
"I said that we see in sport that teams can come back like Liverpool did a few years ago. Stuff like this happens.
"I 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, but we regrouped."