Ireland held firm to beat Scotland 17-13 in a thrilling match in Dublin on Saturday to clinch back-to-back Six Nations titles for the second time in 11 years.
After being denied a bid for successive Grand Slams last week, a sluggish Ireland looked at risk of relinquishing their grip on the title and giving England something to play for in Lyon after eking out an unconvincing 7-6 halftime lead.
Andy Farrell's side showed far more intent straight after the break, pushing hard until Andrew Porter's 65th-minute try put daylight between the sides, only for a late Huw Jones try and an Irish yellow card to set up a nervy finish.
The victory kept Ireland clear of second-placed England, eased the disappointment of another crushing World Cup quarter-final defeat and ensured the post-Johnny Sexton era began with silverware.
"Very special, these days don't come around very often," captain Peter O'Mahony said.
O'Mahony had reminded fans after the Twickenham disappointment that Ireland would have given an arm and a leg for a single title not so long ago.
"We put in a lot of hard work, going back to the World Cup. It was tough but it galvanised us. To come back from that defeat, it shows the character in the group we have," he added.
The veteran Munster back-row forward, who was in tears during the anthems, said before lifting the trophy that the game could be his last for Ireland.
"If it was the last one, I'll be a happy man," O'Mahony said.
The game was punctuated with nerves for the home fans, with Finn Russell putting Scotland 3-0 ahead after a scrappy opening 10 minutes where the ball spent more time being pinged into the air than put through the hands.
The Scots gifted Ireland an opening try with a horror show of a lineout five metres from their own line that flew past all the Scottish jumpers and into the arms of Dan Sheehan who strolled over for his fifth try of the championship.
A tired looking Ireland attack was nowhere near as fluid as it had been earlier in the campaign, conceding eight early turnovers as the visitors blunted what little Ireland had to offer with an organised defence.
The mistakes were not limited to Ireland though as neither side were able to control a forgettable first half.
Ireland came alive after the break, flyhalf Jack Crowley nudging them four points clear before prop Tadhg Furlong was denied a try in a tight call by the officials.
The home side kept coming but knocked on twice with the tryline beckoning as the subdued atmosphere of the first 40 minutes swung between choruses of "The Fields of Athenry" and nervous groans in the second.
After they were held up on the line again, persistent Scottish fouls put replacement prop Ewan Ashman in the sin bin and the breakthrough arrived when the subsequent penalty found its way to Porter who did the rest.
A yellow card for Irish replacement Harry Byrne four minutes from the end ensured a far nervier finish that Ireland would have liked, particularly when Jones cut the deficit to four points but the hosts hung tight and the celebrations began.
