Jonathan Sexton produced an excellent first-half display and surpassed 500 points for Ireland in a 50-7 win over Canada to begin their Rugby World Cup campaign.

Viewed as one the potential winners of the competition, Ireland were never likely to be tested by a Canada team that had lost eight of their last nine Tests.

And Joe Schmidt's team duly made short work of Canada, with the kicking game of fly-half Sexton proving instrumental.

Sexton crossed for one of Ireland's seven tries at the Millennium Stadium, with Sean O'Brien, Iain Henderson Dave Kearney, Sean Cronin, Rob Kearney and Jared Payne also adding five-pointers in a resounding bonus-point success.

The Six Nations champions will next face Pool D rivals Romania at Wembley Stadium a week on Sunday.

Canada were not overawed by the occasion, starting brightly and seeing an early opportunity go begging as Gordon McRorie's ninth-minute penalty from 50 yards fell short.

And just five minutes later it was Ireland who took the lead through a Sexton penalty after a superb kick for touch from the fly-half and a botched Canada line-out had given Schmidt's men possession and territory.

Canada were then reduced to 14 men after 17 minutes when captain Jamie Cudmore was shown a yellow card for illegally knocking the ball away at the ruck.

Ireland instantly took advantage as a dominant rolling maul allowed O'Brien to touch down for the opening try. 

With Cudmore off the field the game quickly developed into a one-sided affair and, shortly after Paul O'Connell had been held up over the line, Ulster back row Henderson overpowered three Canada defenders to crash over for his first try in Ireland colours.

Sexton's conversion took him over 500 Ireland points, and the number 10 marked the occasion with a try of his own in the 28th minute as he sprinted through the Canada backline to go over in the left-hand corner.

Dave Kearney took advantage of an overlap on the right to secure the bonus point with Ireland's fourth try before Canada were denied their opening points of the game in first-half stoppage time as DTH van der Merwe had a try chalked off by the TMO.

Ireland captain O'Connell was sin-binned two minutes after the second-half restart for intercepting from an offside position, but Canada could not take advantage of his absence.

Cronin went underneath the posts for Ireland's fifth try 15 minutes from time, before Van der Merwe got Canada on the scoreboard by taking advantage of Payne's poor kick and racing clear.

Canada's defence crumbled further in the closing stages, Rob Kearney going over for Ireland eight minutes from the end, with centre Payne then completing the rout in the 75th minute.