Not that every single battle isn't a key one when it comes to New Zealand...
If you're finding it hard to remember a more important game in Irish rugby history, that's because there really hasn't been one. A place in the semi-finals awaits, and while that wouldn't even meet the bare minimum that AIG Insurance's All Blacks' fans will be expecting, it's totally uncharted territory for Ireland.
When Ireland claimed their first victory over New Zealand on Irish soil last November, every single player was in top gear. It took an already-injured Peter O'Mahony hounding on top of a ball that would lead to a certain try to win the Man of The Match.
This is the kind of dedication that's needed this Saturday.
Saying that, there are a few key areas on the pitch where the match will be won or lost. We could probably have dedicated an entire piece to every single position, but here are the ones we thought were the most fascinating:
1. Tadhg Furlong v Joe Moody
Despite the fact that New Zealand came up against a behemoth of a Springbok pack, they still boast a 100% scrum success rate. Ireland's is still very strong at 93% (losing seven), but it will be interesting to see how things fare this time out.
While Moody is four years Furlong's senior, he only has three more caps than the New Ross man, 43 and 40 respectively. Ireland will likely be looking to rely heavily on their set piece if they are to stem New Zealand's ability to dominate in open play, and Furlong will be crucial to that effort.
2. Iain Henderson v Brodie Retallick
Unlike the scrum, Ireland have had a slightly better lineout so far during the tournament. With a 95% success rate compared to New Zealand's 92%, it's another area that Ireland will really need to dominate.
What adds extra spice to this one is the fact that it can really go either way. One can't help but think New Zealand would have had a better success rate with Retallick on the pitch, and teams like England, Wales and Japan have put pressure on Ireland's lineout in the recent pass.
If there is another man capable of doing what England's Maro Itoje and Japanese stalwart Luke Thomson did, sadly it's 78-cap Brodie Retallick.
3. Johnny Sexton v Richie Mo'ounga
It goes without saying that out-half is a crucial battle, but especially so when it's two teams with entirely different styles. Mo'ounga will likely look to free the ball and bring in extra playmaker Beauden Barrett as much as possible, whereas Sexton will be looking for a much more controlled game.
Ireland's kicking game will be crucial, and Sexton will likely look to test internationally-inexperienced New Zealand wingers Sevu Reece and George Bridge. While of course both of them have proven to be nothing short of lethal when given space, this is their first time coming up against Ireland's aerial bombardment.
4. Rob Kearney v Beauden Barrett
Few would have thought that moving one of the best outhalfs in the world out of position would be a good idea. When it means you're freeing him up as an extra playmaker, it suddenly makes a lot of sense.
Kearney is likely to be in for a busy 80 minutes covering the back field, especially when his back three partners will be needed in the defensive line. Kearney's experience at marshaling this part of the pitch is what he's best at, and exactly the reason why he pipped the in-form Jordan Larmour for a starting berth.
5. Ireland v Nigel Owens
It's a lot easier said than done, but Ireland simply cannot give New Zealand a chance to put their tails up. Ireland's penalty count has been very good overall this tournament (discounting the three incorrect calls against Japan), and they'll look to continue that.
If Ireland can get on the right side of Owens like they did Wayne Barnes last year (Ireland conceded five penalties to New Zealand's 11), they will be well on their way to a monumental win.
WATCH: Throwback to New Zealand's attempt at hurling
Ahead of their game against Ireland last year, AIG Insurance, who sponsor both New Zealand and Dublin GAA, sent a few All Blacks onto the hallowed turf of Croke Park to have a go at our native sports with 160 kids from Dublin City.
This was done with charity partner Aoibheann’s Pink Tie as part of the AIG Heroes initiative to help support grassroots sport. While historically they are famed for their rugby ability, it's pretty safe to say we have the edge in hurling.
Mind you, with a bit of training we reckon TJ Perenara would do a job at centre half forward...
The AIG Heroes initiative aids the development of future community leaders by promoting sport as a means to build self-confidence & social skills, leadership & teamwork capabilities, & to improve overall health & wellbeing in economically disadvantaged areas. Brought to you by AIG Insurance
