CARDIFF, Wales — Jamie Cudmore is taking responsibility for Canada’s lopsided loss to Ireland in its first pool game of the Rugby World Cup.

The rugby hardman was relegated to the sin-bin in the 18th minute of the eventual 50-7 loss, leaving Ireland to overwhelm the Canadian squad with three tries and a total of 19 points in the 10 minutes spanning the penalty.

"I got to pay the price and that’s on me," Cudmore said. "It was a big mistake."

With the score at 3-0 to Ireland in the 18th, Cudmore was lying on the ground next to the ball at the bottom of a ruck with the Irish on the attack, inches from the try-line when he flicked out a hand and the ball scooted away for the penalty.

Cudmore had barely reached the benches when Sean O’Brien barged over at the base of a rolling maul from an attacking lineout. More bludgeoning paid off when Iain Henderson drove through centre Nick Blevins to reach over and ground in the 25th after a series of phases.

Irish captain Paul O’Connell was sin-binned two minutes in the second half but Canada couldn’t capitalize.

"They made us pay in that area with a man down and we weren’t able to do the same when they were a man down," Canadian head coach Kieran Crowley said.

The Six Nations champion Irish scored seven tries in total under the Millennium Stadium roof.

Jonathan Sexton ran the show from flyhalf, crossing once and kicking nine points to inspire Ireland to a 29-0 halftime lead. Dave Kearney was the other first-half try-scorer.

Sean Cronin, Rob Kearney, and Jared Payne all dotted down in the final 16 minutes for Ireland, which had a troublesome buildup involving consecutive losses to Wales and England in the warm-ups.

Some were questioning whether the Irish had peaked too early after back-to-back Six Nations titles. Perhaps they were simply keeping something back for the World Cup.

Canada didn’t put up the sternest of tests — its sole try came from DTH Van Der Merwe following an interception on halfway in the 68th.

"We put some good rugby together but we didn’t have the finishing in the red zone," Cudmore said. "If we had a few things go our way I think we would have been in the game a bit more."

Kearney capped an impressive first half for the Irish by running onto Luke Fitzgerald’s pass on an inside line and drift around his opposite wing for glide over.

It was already mission accomplished by halftime, and after weathering some pressure soon after the restart, Ireland emptied the bench — giving key players such as Sexton a rest — and saw its replacements bring new energy.

One of them, Cronin, crashed over after multiple phases, Kearney finished off a searing break down the left from Keith Earls, and Payne’s try under the crossbar brought up the half-century.

Ireland leaked its try after Van Der Merwe blocked Payne’s kick-through and sprinted from just inside his own half.

Canada entered the tournament on the back of some good form having won two of its previous three World Cup warm-up matches.

Canada plays Italy next Saturday in its second World Cup match.

"We’re not here to make up the numbers," Cudmore said. "We want to put our rugby in place and compete with the best in the world — obviously on the scoreboard today, we didn’t do that.

"We’re going to stick to our guns, put our game in place, and look forward to Italy."