Warren Gatland wants Wales to win their 'back-yard' scrap with Celtic 'brothers' Ireland.
Wales' head coach has found himself in hot water in the past for claiming his players 'hate' the Irish. He no longer believes that is the case, but admits there is plenty of unfinished business between the rivals.
Gatland said: "There's no bad blood or hard feelings, but when you know each other so well, it's like playing against your brother in the back yard. You want to beat him as much as you can and it will be no different on Saturday.
"There's a lot of rivalry there because the players know each other so well from playing against each other most weeks for their clubs and from the Lions.
"It has been pretty even at international level, but the Irish provinces have had huge success in recent years so a lot of our guys have been used to watching them be pretty dominant."
Just last week Cardiff Blues, Scarlets, Ospreys and Newport Gwent Dragons were all victorious against Irish opposition and Gatland hopes that is an omen.
He said: "It was the first time that has happened since 2010 so it was a big confidence booster for everyone. You could see the guys who were involved coming back into camp with a spring in their step, but Ireland are currently third in the world and have found a style that is proving very successful, so we're under no illusions what is coming our way.
"This game is massive for us. If we win we're still in the Championship, but in the last few games we just haven't been on the edge."
Gatland has kept faith with the side that out-muscled France 20-13 in Paris and that means Sam Warburton will become his country's longest-serving captain when he leads the Dragons for a 34th time.
Gatland said: "It's a fantastic achievement and I hope we reward that achievement on Saturday."
Paul O'Connell will also celebrate a landmark at the Millennium Stadium with his 100th cap as defending champions Ireland chase a Grand Slam and Gatland couldn't resist the chance to deliver a gentle poke the player's way.
Gatland said: "Paul is an exceptional player but, above all, puts the team first. If he delivers a good performance then the team tends to do well."
Wales: L Halfpenny; G North, J Davies, J Roberts, L Williams; D Biggar, R Webb; G Jenkins, S Baldwin, S Lee, L Charteris, AW Jones, D Lydiate, S Warburton (capt), T Faletau. Replacements: R Hibbard, R Evans, A Jarvis, J Ball, J Tipuric, M Phillips, R Priestland, S Williams.