Having had time to review his own performance and that of the team in the 22-10 win over the US Eagles, Sexton is confident that missing out on the try-scoring bonus point will not have a bearing on where Ireland finish in the pool.
"We got the victory over the USA, not in the manner in which we would have liked but there's nothing productive to be gained from dwelling on the match," he wrote in his latest O2 Rugby blog.
"We can render the bonus point issue irrelevant over the next three matches. That's the focus for the team starting with the game against Australia.
"The mood in the camp is good, resolute as we prepare here in Auckland for Saturday's clash with the Wallabies."
The out-half was frustrated by Ireland's failure to turn their pressure into points against the Americans, even if the wind and rain did hamper ball handling and place-kicking conditions.
Sexton, Jonny Wilkinson and Chris Paterson were among the kickers who ran into difficulty from the kicking tee over the tournament's opening weekend, with the Dubliner missing four of his six shots at the posts.
"The conditions were very stormy, there was excessive wind and driving rain for the most part but as a team we were hoping for a better display despite the elements," he admitted.
"On a personal level it wasn't one of my best games. The irony is that I had been kicking well in the warm-up but the wind changed direction on a couple of occasions during the match.
"I was happy with the manner in which I struck the first couple but less so with a couple of efforts after half-time.
"The stadium itself is quite open - it's not encased by stands - and therefore the wind tends to swirl as it sweeps through openings."
The two-time Heineken Cup winner added: "Several of the top tier nations have pool matches in some of the smaller stadiums and if the weather doesn't play ball then kicking conditions are a lot more difficult.
"It's not an excuse, just an observation. Much has been made of the ball by some commentators but there's no problem there."
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