Ireland cannot afford to stick rigidly to one gameplan and must be willing to adapt if they are to defeat New Zealand on Saturday, says Johnny Sexton.

However Sexton has warned such a style will not always be possible.

"We've always had license to do that, but if teams show a different picture you can't do it all the time," he said.

"That's just the way the game unfolded on Saturday. We'd love to do it all the time and we just got presented the pictures and we read them quite well and executed off the back of it."

The free-flowing display that proved far too much for Japan was met with widespread approval in Ireland, with fans hoping it was a sign of things to come under Andy Farrell.

Sexton acknowledged that against the number one side in the world Ireland are unlikely to be afforded the same license to thrill as they were against Japan, who by their own admission were far from their best in Dublin.

"If a team comes and they put 14 guys on the front line you can't run, you've got to kick more or target a different space," continued Sexton, who scored 16 points on his 100th cap.

"If it comes and it's raining or the conditions are really bad or they play a different type of defence to what Japan showed us, then we'll play the right options as we see fit.

"The most important thing is that we win, that's what we're judged on. Yeah it's great getting plaudits for how we played on Saturday - we showed bits of that during the Six Nations but I think the pleasing part about it was that it was a bit more consistent this week."

'Try-scoring defence' the target against red hot All Blacks

New Zealand arrive in Dublin for the penultimate game of their season having already broken the world record for most points and tries scored in a calendar year.

Despite a disjointed performance they still put up 47 points in a seven-try win over Italy last Saturday, for which several of their key players were rested before back-to-back Tests against Ireland and France.

In the aftermath of his side's win over Japan, Irish head coach Andy Farrell said it was the defensive effort of his team that pleased him most, and they will require an even bigger effort if they are to stifle the free-scoring All Blacks.

"It's a bit of mentality to try to go and get the ball back," said full-back Hugo Keenan.

"I suppose just forcing them under pressure and trying to not defend for too many phases. You can call it try-scoring defence. There were a few examples of that [against Japan] whether it was kicks long, the kick chase that was very good, Andrew Conway or Iain Henderson forcing mistakes and benefiting on the back on that.

"It's something we've been working on. Si [defence coach Simon Easterby] has been leading it well and a few lads are taking ownership to lead the D.

"It's something that we felt at the start of this camp that we could really improve on and I think that's a good standard to what it should be like."