Cardiff - Playing alongside each other in Lions colours, Wales centre Jonathan Davies combined with Irish halfbacks Connor Murray and Johnny Sexton to thwart double world champions New Zealand two years ago.
But it will be gloves off come Saturday's Six Nations game in Cardiff, where a victory for Wales would ensure a Grand Slam.
"We have to cut their time down and make sure we make them make tackles and become tired so when it comes to those key decisions they are not as fresh as they would be at the start of the game," Davies said of facing scrum-half Murray and World Rugby player of the year in outside-half Sexton.
"Having played with them they are two great players and we have to be at the top of our game to make sure we do not give them the opportunities to put Ireland into the areas they want to play in."
Scarlets centre Davies, who spent two seasons at Clermont, was voted player of the series which the Lions drew 1-1 with the All Blacks in 2017.
For Wales, he was named defensive leader by assistant coach Shaun Edwards, the Great Britain rugby league legend, and has been instrumental in headlining a formidable Welsh defence that has leaked only six tries in this campaign, the least of the six teams. Wales also produced 140 tackles in the second-half of the brutal 18-11 victory over Scotland last week.
"It is a system Shaun has had for a number of years. You get comfortable working with the same person for those years," Davies said.
"Shaun has been excellent for Wales and whenever Wales have done well in the Six Nations, our defence has been at the forefront. It is having the confidence in the boys inside and outside of me."
Ireland, Davies argued, would offer up a testing proposition.
"They are second in the world. They have been excellent," he said.
"They were maybe caught a bit cold by England" in their opening game, losing 32-20.
"They have grown and grown. They have great tacticians at 9 and 10 and for us it is making sure we do not give them time to take a stranglehold on the game because once they do get that foothold there is no one really better than those two.
"We have to make sure we keep doing what we are doing and execute what Shaun has prepared."
Wales overcame a seven-point half-time deficit to beat England 21-13, effectively nullifying the threat of half-backs Ben Youngs and Owen Farrell.
"It is one of the areas we are looking to keep going," Davies acknowledged.
"It has been pretty good throughout the whole campaign. The half-backs we have played against have not really taken full control of the game. There have been periods when we have bent a bit but we have not broken.
"We have to make sure that when we have opportunities to put them under pressure we really do."
Davies admitted that a Grand Slam victory over Ireland would be a massive boost going into a Rugby World Cup year.
"It would be good to keep the momentum we have built up over the last 12 months going," he said.
"Ireland are an excellent team. Just to get a win over them given what they have achieved over the last 18 months or so would be excellent for us moving forward.
"It is a massive game and the boys are really excited."
15 Liam Williams, 14 George North, 13 Jonathan Davies, 12 Hadleigh Parkes, 11 Josh Adams, 10 Gareth Anscombe, 9 Gareth Davies, 8 Ross Moriarty, 7 Justin Tipuric, 6 Josh Navidi, 5 Alun Wyn Jones (captain), 4 Adam Beard, 3 Tomas Francis, 2 Ken Owens, 1 Rob Evans
Substitutes: 16 Elliot Dee, 17 Nicky Smith, 18 Dillon Lewis, 19 Jake Ball, 20 Aaron Wainwright, 21 Aled Davies, Dan Biggar, 22 Owen Watkin
Rob Kearney; Keith Earls, Garry Ringrose, Bundee Aki, Jacob Stockdale; Johnny Sexton, Conor Murray; CJ Stander, Sean O'Brien, Peter O'Mahony; James Ryan, Tadhg Beirne; Tadhg Furlong, Rory Best (capt), Cian Healy
Substitutes: Niall Scannell, David Kilcoyne, Andrew Porter, Quinn Roux, Jack Conan, Kieran Marmion, Jack Carty, Andrew Conway