The 24-year-old wins his first Ireland cap on Saturday having spent the majority of his career in the shadow of Argentine great Contepomi since making his Magners League bow with the Dubliners back in the 2005/06 season.
Sexton made 37 Magners League appearances for Leinster over the previous four campaigns but always seemed to be overlooked when it came to the must-win matches.
But that has now all changed and Sexton is finally, without question, Leinster's number one No10.
The former Leinster Schools, U-21 and 'A' regular has featured in each of his side's seven Magners League games so far this season and is open enough to admit that the frustrations of being a regular fixture among the replacements for so long have ultimately been good for him in terms of the bigger picture.
"Obviously I'd be lying if I said I was happy to be sitting on the bench rather than playing," Sexton told the Irish Times.
"But, looking back now, I kind of had to bide my time a bit. I felt I learnt a lot while I was sitting on the bench.
"I learnt a lot from Felipe and I'm probably better now for learning from those experiences than I would have been had I been thrown in then."
Sexton's fortunes changed 12 months ago when Ireland coach Declan Kidney gave him a shot with his country's 'A' team.
Although he appeared in the same number of games for Leinster in 2007/08 as he did last season, his role became more high-profile after Kidney's show of faith. And when Contepomi saw his season ended by injury in early May, Sexton stepped up to become a household name for more than those inside Dublin's city walls.
"I suppose I wasn't getting picked much around Christmas time last year for Leinster. Then Declan gave me a big shout, putting me in the 'A' team," added Sexton.
"I've sort of gone on from there. I've been happy with my form ever since so that was probably a big break for me because it was that performance that probably got me back in the Leinster team and I pushed on from there."
And push on he has. Sexton is one point shy of the 100-mark in this season's Magners League and was among the replacement's for Ireland's nail-biting draw with Australia at the weekend.
The secret? Trusting himself and learning to relax.
"I suppose I've not been trying as hard to make things happen,. I was probably trying a bit too hard at the start of last year. I just relaxed a little bit. Now I'm not concentrating on mistakes but I've a more positive outlook."
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