England beats Ireland 23-22 with a last-gasp drop goal by Marcus Smith at Twickenham, blowing open the Six Nations. 

Ireland, rattled by an inspired England, gathered enough composure to be seconds away from clinching back-to-back titles on Sunday morning (AEDT).

But England, trailing 22-20, produced one last attack and took it to the Irish try-line, where it received consecutive penalty advantages as the clock moved into red. If the play had broken down, Smith would have had a penalty kick to win the match. Instead, he snapped off a drop goal from inside the 22 to win it.

"I thought, 'Why not?'" said Smith, who came off the bench for his first rugby in seven weeks after a pre-tournament calf injury.

Ireland's back-to-back Grand Slam hopes went up in smoke but it can still retain the championship with a win or draw when it hosts Scotland in next weekend's last round.

"For large parts of the game, I thought we were a little bit off, and that's down to England, but I felt we had the resilience to keep bouncing back," Ireland coach Andy Farrell said.

"England found a way in the end. They really deserved to win.

"We have been very good at winning. We have to be good at losing. We have to make sure we review that properly and come into work on Monday with a smile on our faces because there is a championship to win."

The defeat ended Ireland's 11-win streak in the championship, tied for the record with the England of 2015-17.

The result ended a four-match losing run to Ireland and England goes to France next weekend.

"I am so proud, we came under a lot of negativity after that Scotland game," England captain Jamie George said.

"We have known that something special was coming, we had a huge amount of belief. Are we one of the best teams in the world? No. But do we have the best people in place? Absolutely."

Meanwhile, Italy won a Six Nations match at home for the first time in 11 years after overcoming Scotland 31-29 at a sold-out Stadio Olimpico.

The win Italy had been threatening but squandered against England and France last month finally came to fruition, but the Azzurri had to come from 22-10 down after 35 minutes.

Italy scored the next 21 points to lead again from the 57th. Scotland scored a bonus-point fourth try with two minutes to go and went after the win it desperately needed to stay in the title hunt. The Scots reeled off 28 phases and the clock went into red as they moved upfield, until Blair Kinghorn's offload to Sam Skinner was knocked on and Italy finally secured a precious win.

The Italians fell over themselves in teary celebrations as a full house of 69,689 erupted.

"We gave everything and I couldn't be prouder," Italy captain Michele Lamaro told broadcaster ITV.

"I believe 100 per cent this team can play games like this, we proved it two weeks ago [against France].

"We still have to improve a lot, but to bring back a win in Rome is unbelievable."

It was Italy's first home win in the championship since 2013. It ended a losing streak of 26 home matches in the championship, and a streak of 30 at the Stadio Olimpico.

Italy has been most successful in the Six Nations against Scotland but this eighth win came nine years after its last over the Scots.

Defeat has dashed the title hopes of Scotland, which started in Rome as an 18-point favourite.

Italy has earned its most competition points — seven — since it joined the championship in 2000, and will face Wales in the final round next weekend with a chance to avoid the wooden spoon for the first time since 2015.

"Italy played better in the second half and got more points than us so of course they deserved it," Scotland coach Gregor Townsend said.

"We came out in the second half and got the contact area sorted and created a score. But it was disallowed and after that we were ill-disciplined. We gave away about six penalties in a row which let them back in the game."

Italy's Ignacio Brex paid tribute to his team's spirit after the match.

"We showed the world we have the passion in the last few minutes," Brex said.

"If you are tired, it's not a problem, it's in our blood."

AP