World Rugby revealed the reimagined Pacific Nations Cup this week, a six-team annual competition featuring Canada, Fiji, Japan, Samoa, Tonga, and USA.
England were forced to dig deep in an 18-17 victory over Samoa that will have left probable World Cup quarter-final opponents Fiji licking their lips.
England qualified for the quarter-finals of the World Cup after Japan saw off 14-man Samoa 28-22 in Toulouse to keep alive their own hopes.
Emiliano Boffelli was the difference-maker as Argentina survived a late charge to beat Samoa 19-10 and reignite their Rugby World Cup campaign.
Samoa scored four tries in the second half to power to a 43-10 win over Chile in their Rugby World Cup clash Pool D in Bordeaux on Saturday.
Billy Vunipola has been banned for the start of England's World Cup campaign after receiving a three-week suspension for his red card against Ireland.