* Sexton scores bonus point try a minute before halftime
* Ireland to face New Zealand or South Africa in quarters
By Ian Ransom
FUKUOKA, Japan, Oct 12 (Reuters) - Ireland played with 14 men for 50 minutes but still eased into the Rugby World Cup quarter-finals with a seven try, 47-5 demolition of a ragged Samoa in their final Pool A match on Saturday.
Centre Bundee Aki became the seventh player to be shown a red card at the tournament when he was sent off at Fukuoka Hakatanomori Stadium for a high tackle on Samoa flyhalf Ulupano Seuteni in the 29th minute -- but Ireland were already 21-5 up at that stage.
Flyhalf Johnny Sexton earned the bonus point that secured their passage with his second try just before halftime and skipper Rory Best, prop Tadgh Furlong, fullback Jordan Larmour, number eight CJ Stander and winger Andrew Conway also crossed.
Fukuoka escaped the violent storm that forced the cancellation of Saturday's other two matches but Typhoon Hagibis could still prevent Japan playing Scotland on Sunday to decide if Ireland next face the champion All Blacks or South Africa.
Having lost to Japan and laboured to victory over Russia after a dominant opening win over Scotland, Ireland needed to make a statement and came into Saturday's match with a near-full strength side, boosted by centre Robbie Henshaw's return from a hamstring strain.
The unstable state of the pitch was a talking point in the lead-up, and despite the attentions of a team of ground staff, it was badly chopped up by halftime.
Samoa's defence was as ragged as the playing surface and it crumbled against the first Irish shove from a lineout drive, with Best touching down from the back of a maul in the fourth minute.
Two minutes later, Samoa were down to 14 men with hooker Seilala Lam drawing a yellow card for a high tackle on Jacob Stockdale.
Ireland wasted no time in stretching their opponents, with quick hands finding battering ram Furlong, who planted the ball over the line after bursting through four defenders.
By the start of the second quarter, Ireland were 21-0 up, with jet-heeled winger Larmour setting up Sexton's first try with a brilliant linebreak and inside pass near the right corner.
It took a loose Irish pass and intercept for Samoa to get their first points, with captain Jack Lam completing a furious drive over the line.
The game then threatened to turn Samoa's way when Aki was sent off by referee Nic Berry.
But Ireland responded brilliantly, pushing the Samoans back over the gain-line and soon winning a penalty scrum at the five-metre line.
Murray whisked the ball wide to his halfback partner and Sexton easily split two defenders to claim the bonus point try near the left corner a minute before the break.
Aki's absence was barely noted after the re-start as Ireland starved the Samoans of possession and rumbled forward.
Lethal behind the scrum, Murray found Larmour at the right corner with a cut-out pass and the young fullback's converted try blew the lead out to 33-5.
Ireland's forwards maintained the pressure and Samoa soon had a second man sent off, with TJ Ioane drawing yellow near the hour-mark for a ruck infringement.
With team numbers back to parity, Samoa were soon pinned on their goal-line, with number eight CJ Stander eventually crashing over for Ireland's sixth try.
The game descended into an exhibition, as replacement flyhalf Joey Carbery threaded a grubber kick through the Samoan line, allowing Conway to dot down 10 minutes from the siren to spark a chorus of singing by Irish fans. (Reporting by Ian Ransom; Editing by Ken Ferris)