Ireland secured their fourth Grand Slam but first in front of the passionate Dublin home crowd after wrestling their way past 14-man England in a tense Six Nations finale in Dublin.
France and Ireland were the two teams looking to claim the Six Nations title on Saturday, and the former did their bit by beating Wales in the day's second fixture.
Scotland and Italy played out an entertaining game with the hosts winning at Murrayfield in the opener, but the headlines ultimately belonged to Ireland on a special day in the capital as they triumphed 29-16 over England to seal a perfect campaign.
Ireland knew what they had to do against England ahead of kick-off, but playing in the evening seemed to add to the tension for all involved.
The home fans were a little on the nervous side at the Aviva Stadium when Owen Farrell scored two early penalties to put England ahead, only for a well-worked Dan Sheehan try to settle the hosts down as they took the lead for the first time.
Before that, Ireland captain Johnny Sexton scored an historic penalty to get his side up and running, as he surpassed Ronan O'Gara as the competition's record scorer with a nerveless penalty.
With Sexton also converting the game's opening try, Andy Farrell's side led 10-6 going into the break, but their chances of winning were given a huge shot in the arm when England full-back Freddie Steward was sent off just before the interval.
Steward saw red after colliding with Hugo Keenan, and while the call could have gone either way, it certainly did Ireland no harm in coming out on top.
England did not go down without a fight, though, Farrell reducing the deficit to 10-9 with his third penalty, but when Ireland had the chance to score, they took it with both hands.
Robbie Henshaw and Rob Herring both crossed over with well-worked tries, either side of Sheehan's second of the game as the hosts' class told in the end.
England did manage to score a deserved try through Jamie George in a much improved performance from last week, but the day ultimately belonged to Ireland and Sexton.
Saturday's victory ensured Ireland won their first Grand Slam in five years in what was Sexton's final Six Nations appearance.
He told BBC Radio 5 Live after the game: "You could not make this up; it is like living in a dream. We did not play our best but what a team. What a group of coaches.
"We did nothing that they told us, in fact, the exact opposite, but we made things hard for ourselves.
"England are a top-class team. To get a win on St Patrick's weekend is unbelievable. We did not quite nail it, but we did enough.
"It is the best tournament to play in, the best country to play for. We are so proud to be Irish. It does not feel like the end; there is plenty left in this team, we need to improve on today, and we will be back."
Earlier in the day, France ended their Six Nations campaign in style by beating Wales 41-28.
Les Bleus racked up another bonus-point win on home soil, even though it was Wales who scored first, with George North crossing over early on.
France responded with two tries from Damian Penaud before further efforts from Jonathan Danty, Uini Atonio and Gael Fickou took Les Bleus away from the Dragons.
Thomas Ramos helped them further with 16 points from his trusty boot, although Wales did show some fighting spirit under Warren Gatland, with tries from Bradley Roberts, Tomos Williams and Rio Dyer.
While it was a disappointing day for Fabien Galthie's side, they will head into the World Cup on home soil this year with every chance of success.
Galthie's men are 11/4 to win World Cup 2023, while New Zealand remain their closest rivals at 3/1 ahead of Ireland at 4/1.
Scotland secured third spot in the Six Nations ahead of England thanks to a narrow 26-14 victory over Italy at home, made sure only by Blair Kinghorn's last-gasp length-of-the-field score, which completed his hat-trick.
Gregor Townsend's side perhaps gained confidence from their bonus-point victory, although it was anything but easy during an intense battle against the Azzurri at Murrayfield.
With Italy down to 14 before half-time, Scotland punished them with tries through Duhan van der Merwe and Kinghorn.
Rather than lie down, Italy went for broke towards the end, and a try from Tommaso Allan and a penalty from Paolo Garbisi gave them a glimmer of hope.
However, with the pressure on, the hosts managed to hold out before breaking away at the death, with Kinghorn's third score, with Italy feeling it was another opportunity that they let slip by.
Overall, Scotland - 25/1 to win the World Cup - will take plenty of pride from their third-place finish, while Kieran Crowley's men finished with the wooden spoon that was perhaps undeserving, given some of their play in this campaign.