Motu Matuu of Samoa attempts to tackle Nathan Hirayama (R) of Canada during their World Rugby Pacific Nations Cup match in Toronto yesterday.

AFP/Toronto

Samoa scored a last-gasp try to defeat Canada 21-20 and set up a Pacific Nations Cup final showdown with arch-rivals Fiji here yesterday.
The powerful Samoans looked to be slipping to a shock defeat after Canada’s Sale Sharks wing Phil Mackenzie raced over for an opportunistic converted try to put the home side 20-16 up with four minutes left.
But Samoa punished a needlessly conceded penalty by setting up a line-out on Canada’s goalline with just seconds left.
And when Canada knocked on from the setpiece, Sakaria Taulafo was on hand to snaffle the ball and flop over the line for the score to give Samoa a 21-20 lead.
The Samoan victory dashed Tonga’s hopes of snatching a place in the final against Fiji on Monday.
Earlier, Canada had looked poised to score an upset, racing into a 13-0 lead through a try from centre Nick Blevins and eight points from the boot of fullback James Pritchard.  
Samoa responded with a penalty from Michael Stanley to make it 13-3 at half-time.
The Samoans looked to have got a grip on the contest during the second half, scoring an early try through Anthony Perenise converted by Stanley.  
Two more Stanley penalties put Samoa into a 16-13 lead before Mackenzie’s late effort put Canada back in front until Taulafo’s late winner.
Earlier, Fiji withstood a furious late onslaught from Japan to book their place in the final with a 27-22 victory.  
The Fijians finished a see-saw battle against the 2014 champions with two players in the sin-bin as Japan pressed desperately for a match-winning score that would have completed a remarkable comeback.  
The Japanese had taken an early lead through three penalties from fullback Ayumu Goromaru before Fiji hit back with a devastating 10-minute spell.  
Tevita Cavubati, Joshua Matavesi and Metuisela Talebula all crossed for converted scores as Fiji, which also scored a Matavesi penalty, transformed the contest to take what looked like an unassailable 24-9 lead at half-time.
But Japan came roaring back after the restart, with right wing Akihito Yamada dotting down in the corner to make it 24-14.
Goromaru missed the conversion but slotted a further penalty to reduce Japan’s deficit to 24-17 after 52 minutes.  
Matavesi restored Fiji’s 10-point cushion with his fifth successful kick of the day to make it 27-17 but Japan hit back once again through their powerful scrum.  
A superb pick-and-go by New Zealand-born number eight Hendrik Tui saw the back rower crash over from close range to make it 27-22.
Goromaru missed the conversion, however, meaning the Japanese would need a try to secure parity.  
In a frantic finale, the Japanese looked poised to claim the win as Fiji’s composure deserted them.  
Second row Leone Nakarawa was sent to the sin-bin in the closing minutes and was joined as the seconds wound down by loosehead Campese Ma’afu.
Despite the advantage, Japan were unable to find a way through and eventually conceded a penalty with the last kick of the game as an exhausted Fiji held on for a nervy win.
Earlier, Tonga completed their group stage campaign with a 33-19 victory over the United States.