Ireland has a sniff of its first Six Nations rugby title in five years after humbling defending champion Wales 26-3 at Lansdowne Road on Saturday.
Ireland scored the game's only two tries from superb rolling mauls while Jonathan Sexton kicked four penalties, his only miss from beyond halfway.
By contrast, Wales' only shot in anger was a second-half try disallowed, while Ireland's superior discipline gave Leigh Halfpenny only one penalty kick, nearly an hour in.
Wales, trying to become the first team to win the championship three successive times outright, promised to be direct and physical but was overwhelmed by a swarming defense and forced into multiple errors; 15 penalties and two free kicks, 16 missed tackles, 10 turnovers, two chargedowns.
Wales paid for it with a first away loss in the championship since 2011, when it also last failed to score a try.
Coach Warren Gatland, following Wales' biggest Six Nations defeat in his seven-year tenure, called it his lowest moment.
"We won't be thinking in terms of retaining the Six Nations, we'll be thinking about improving for our next game against France,'' he said.
Gatland was taken aback by Ireland's rugged defense, and his side conceding 17 penalties and free kicks.
"I can't remember any occasion when they moved the ball through the backline at us,'' he said. "They dominated us up front and caused us a lot of problems. We have a target of 10 (penalties) or loss, so to give 17 away was simply unacceptable.''
After two successive wins for the first time since 2010, Ireland was in pole position for this year's title, though it must win at least one of its two away games, against England next in two weeks, or France in the tournament closer next month.
"I'm not going to think too far ahead,'' Ireland coach Joe Schmidt said. "But it's certainly a gathering of confidence for us.''
He said replacement lock Dan Tuohy may have a broken forearm.
The 13-0 halftime score fairly reflected Ireland's control. By the time Sexton kicked them 6-0 ahead in the 17th minute, Wales had conceded five penalties to one. The scrums were a mess for both sides but the lineout was an Irish pressure point, thanks to O'Connell and Devin Toner.
Even in the collisions, the Welsh came off second best. Scott Williams cut down Irish opposite Brian O'Driscoll, who was winded for a bit, but it was Williams who soon walked off cradling his right shoulder.
With Wales putting out a dozen Lions to Ireland's nine, some big Welsh names were left in the shade: Gethin Jenkins and Adam Jones by Cian Healy and Mike Ross in the front row, Sam Warburton and Dan Lydiate by Chris Henry and Peter O'Mahony in the loose, and George North and Alex Cuthbert by Andrew Trimble and Dave Kearney on the wings. Sexton, Paul O'Connell, Toner were also Irish standouts.
Wales coming off second-best everywhere was no better encapsulated than about half an hour in.
Wales earned a lineout throw-in on the Irish 22, but Wales blew the lift and Toner didn't even have to jump to take the gift catch. Moments later, Wales turned over the ball near halfway and Sexton had the foresight to realize Halfpenny was up near the play, so he kicked down the line and No. 8 Jamie Heaslip forced Rhys Priestland to run the ball out. Given an attacking lineout five meters out, Toner took the catch, handed the ball to Henry, and the flanker was trailered in a fast rolling maul into the right corner for his first test try. Sexton converted from the touchline.
After Sexton made it 16-0 in the 46th, Irish fans began singing, their confidence rising.
When Halfpenny, on the occasion of him becoming the youngest Wales player to 50 caps at 25, finally kicked their first points, O'Mahony drew a second penalty for Ireland and Sexton delivered.
Wales' one try chance came after scrumhalf Mike Phillips tapped two consecutive penalties and replacement prop Rhodri Jones burrowed over but he was penalized for a double movement.
In the last minute, Ireland expressed its power again when it rolled a maul from a lineout 20 meters out, which sucked in so many Welshman that replacement flyhalf Paddy Jackson ran in untouched, until Liam Williams dropped an elbow on his face. Jackson still had the last say, with the conversion.