Ireland face Wales on Sunday hoping for their first Six Nations victory in Cardiff for eight years but up against a team desperate to make amends for a terrible campaign in 2020.
Andy Farrell's men travel to the Welsh capital boosted by four straight wins over their opponents but seeking to improve on last year's disappointing third-placed finish in the Championship.
Wales suffered a major fall from grace in 2020 - finishing fifth in the table under new coach Wayne Pivac after winning the Grand Slam the previous year.
Here, AFP Sport picks out three talking points ahead of the match:
"It is a huge game for both teams, and will be a war of attrition," is how Ireland coach Farrell assessed Sunday's clash.
Farrell may not have received an A-plus for his first year in charge but the man under more intense pressure is Wales counterpart Pivac.
The New Zealander's honeymoon period after taking over from compatriot Warren Gatland was short - Wales won just three times in 10 outings last year.
Pivac will be looking for a significant improvement for the team, who were World Cup semi-finalists in 2019 under Gatland.
"For us within the Welsh camp, it's one that we're looking forward to because we want to be better than we were last year, clearly," said Pivac.
"We need to be."
Ireland captain Johnny Sexton said this week that a new face could shake things up in the camp.
He will hope the arrival of Irish great Paul O'Connell to coach the forwards proves his point.
One of O'Connell's key tasks will be improving the line-out, which let the side down last year.
Sexton, one of several players still in the side who played when Connell captained Ireland, said the former lock had already had a "great impact."
"He was selfless as a captain - everything he did was with the team in mind and it is the same now as a coach," said the skipper.
The 41-year-old former Munster player hopes being honest with his former team-mates will prevent any tensions creeping into their relationships.
Sexton said the players must keep their side of the bargain.
"We have to go out and show we are able to put into practice what he (O'Connell) said," the flyhalf explained.
Captains Sexton and Alun Wyn Jones are both 35 but they still set the tone for their teams through their words and actions on the pitch.
Sexton embarks on his 12th Six Nations campaign after shaking off his latest injury while Jones is returning from a serious knee problem.
Both sides will hope their talismen stay on for long enough to influence the outcome in a match-up that has proved feisty in recent years.
Sexton, the 2018 world player of the year, is still relishing the role of captaincy.
"I would hate not to be doing it, that's the right way of putting it," he said.
Farrell is in no doubt the role has fitted him perfectly, even if Sexton was criticised last year for showing his displeasure at being replaced in the Six Nations defeat by France.
"He's got more subtleties into the leadership aspect of his game which I think is going to benefit his game in general as well," said Farrell.
Jones, who has a world-record 152 Test caps, including his outings for the British and Irish Lions, is set for his first game since suffering a knee injury in early December.
The lock is still regarded as a key figure in Pivac's Wales set-up and they need him fit and firing.
15 Leigh Halfpenny, 14 Louis Rees-Zammit, 13 George North, 12 Johnny Williams, 11 Hallam Amos, 10 Dan Biggar, 9 Tomos Williams, 8 Taulupe Faletau, 7 Justin Tipuric, 6 Dan Lydiate, 5 Alun Wyn Jones (captain), 4 Adam Beard, 3 Tomas Francis, 2 Ken Owens, 1 Wyn Jones
Substitutes: 16 Elliot Dee, 17 Rhodri Jones, 18 Leon Brown, 19 Will Rowlands, 20 Josh Navidi, 21 Gareth Davies, 22 Callum Sheedy, 23 Nick Tompkins
15 Hugo Keenan, 14 Keith Earls, 13 Garry Ringrose, 12 Robbie Henshaw, 11 James Lowe, 10 Johnny Sexton (captain), 9 Conor Murray, 8 CJ Stander, 7 Josh van der Flier, 6 Peter O'Mahony, 5 James Ryan, 4 Tadhg Beirne, 3 Andrew Porter, 2 Rob Herring, 1 Cian Healy
Substitutes: 16 Ronan Kelleher, 17 Dave Kilcoyne, 18 Tadhg Furlong, 19 Iain Henderson, 20 Will Connors, 21 Jamison Gibson Park, 22 Billy Burns, 23 Jordan Larmour