Ireland retained the Six Nations title as they overcame a heroic defensive effort by Scotland in Dublin.

Scotland defended bravely after the break as Tadhg Furlong and Robbie Henshaw both had Irish tries ruled out.

Andrew Porter crossed to provide Ireland with clear daylight before Huw Jones gave Scotland late hope.

Ireland, however, steadied themselves in the closing moments to defend their crown in a remarkably tense conclusion to their campaign.

The result also ends England's hopes of snatching the title from Ireland before they face France in Lyon in the tournament's final match at 20:00 GMT.

England ended Ireland's bid to become the first Six Nations team to win back-to-back Grand Slams at Twickenham last week, but by retaining the championship Andy Farrell's side reaffirm their status as the northern hemisphere's leading team.

Nervy first half in Dublin

Having been humbled by England last week, Ireland came into Saturday's match in Dublin under increased pressure as they looked to clinch their sixth Six Nations title knowing a win or draw would be enough to finish the job.

But the pressure showed. While Sheehan was gifted a try from a Scotland line-out, Ireland lacked intensity and struggled to build momentum against a stubborn, well-drilled visiting defence and resultingly went in at the break ahead by the slimmest of margins.

While Scotland were not able to put enough pressure on the Irish tryline in the opening 40 minutes, the away side's defence looked comfortable dealing with Ireland's attacks, gradually sucking the atmosphere out of Aviva Stadium during a flat, cagey first half.

Scotland came to Dublin hoping to win the Triple Crown for the first time since 1990. With Sheehan's try sandwiched between two Russell penalties, those hopes remained intact with the game on a knife-edge at the break.

Ireland wear down Scots to take title

Ireland looked a different animal in the second half, and after a Crowley penalty stretched their lead to four, the home fans roared when Furlong powered over the Scotland line at the end of a sustained Irish attack.

The joy was short-lived, though, after the television match official (TMO) ruled that the prop lost it forward.

While the pressure on the Scotland defence grew, Ireland were further frustrated in their attempts to create clear daylight when Calvin Nash charged towards the line, only to be held up before dropping the ball.

Another chance went begging when a handling error denied Garry Ringrose a try on his first appearance in this year's championship.

Henshaw was also denied a try by the TMO but after Scotland replacement Ewan Ashman was shown a yellow card following a build-up of infringements, Ireland snatched the elusive second try when Porter forced his way over.

With mistakes creeping into a tiring Scotland defence, and with the Fields of Athenry reverberating around the stands, it looked as though Ireland had done enough to carve out the win they needed.

However, their path to victory was complicated when replacement back Harry Byrne was yellow-carded for his tackle on Russell.

And when Jones broke through to score Scotland's only try, Irish nerves intensified once more.

They were not to be denied though, and while they were forced to wait after beating Scotland on Super Saturday in 2015 before taking the title, they were able to lift the trophy after full-time and begin another Irish party on St Patrick's weekend.

This was Ireland's 10th successive win over Scotland, and while not quite as one-sided as their 36-14 victory in last year's World Cup, they again proved too much for Townsend's side.

Despite the ultimate goal of another Slam passing them by, Irish rugby remains in rude health before a two-Test series against world champions South Africa in the summer and an autumn programme that includes a rematch with the All Blacks, who knocked them out of the World Cup.

This will be Farrell's last Six Nations until 2026, of course, with the Englishman taking a leave of absence from his Ireland role to lead the British and Irish Lions tour to Australia next year.

But given the depth of this Ireland squad, no matter who leads the team for their Six Nations hat-trick bid, it will take a mighty effort from one of their rivals to steal the title away from Dublin.

For Scotland, it is another Six Nations campaign that ultimately ends in disappointment. While their hopes of a first championship triumph were effectively washed away by a shock defeat in Rome last week, they arrived in Dublin hoping to seal the Triple Crown of the professional era.

Townsend said his side needed to produce "something special" to beat Ireland and while their defensive effort was to be admired here, they will be left to reflect on what might have been after following their impressive win over England with two defeats.

Line-ups

Ireland: Larmour; Nash, Henshaw, Aki, Lowe; Crowley, Gibson-Park; Porter, Sheehan, Furlong; McCarthy, Beirne, O'Mahony (capt), Van der Flier, Doris.

Replacements: Kelleher, Healy, Bealham, Baird, Conan, Murray, H Byrne, Ringrose.

Sin-bin: H Byrne (76)

Scotland: Kinghorn, Steyn, Jones, McDowall, Van Der Merwe, Russell, White; Schoeman, Turner, Z Fagerson, Gilchrist, Cummings, Christie, Darge, Dempsey.

Replacements: Ashman, Sutherland, Sebastian, Skinner, M Fagerson, Horne, Redpath, Rowe.

Sin-bin: Ashman (65)

Match officials

Referee: Matthew Carley (Eng)

Touch judges: Karl Dickson (Eng) & Christophe Ridley (Eng)

TMO: Marius Jonker (SA)