Holders New Zealand fought off a late Samoa comeback to begin the defence of their World Cup crown with a victory.
The Kiwis took control early on in the Group B match at Warrington, with captain Simon Mannering crossing for two of their four first-half tries. Manu Vatuvei added two more tries after the interval but Samoa, from 32 points down, battled back in superb fashion.
New Zealand were made to wait 11 minutes for their first score of the game but then raced into a 22-0 lead with four tries in quick succession.
The quartet of touchdowns came from full-back Josh Hoffman, two from loose forward Mannering and winger Roger Tuivasa-Sheck after gaps were exploited on the right touchline.
Samoa fought back and enjoyed a long spell of pressure before the interval, finally getting their rewards when half-back Ben Roberts jinked past two tackles to dive over.
Two Kiwi tries in the opening five minutes of the second period, courtesy of Vatuvei's towering take of a high kick and an expansive effort from Luke, looked to have killed off any hopes of an unlikely comeback.
Vatuvei went over again in the corner before the underdogs, roared on by a sell-out crowd. Centre Joseph Leilua rounded off a flowing move, prop Penani Manumeasili touched down for an opportunist third try and, as New Zealand's defence struggled to cope with another barrage of pressure, the swing in momentum brought Samoa to life.
Tries from forward Suaia Matagi and winger Antonio Winterstein reduced the deficit to 12 points, while Williams' unfortunate slip over the dead-ball line with a match-clinching score at his mercy stunned a rattled New Zealand side still further.
But Samoa ran out of steam in the final 10 minutes and Vatuvei took advantage of the open space afforded to him on the left touchline to end Samoa's hopes of a heroic victory.
