Defending champions New Zealand survived a late fight-back from Samoa to claim a 42-24 victory at the Halliwell Jones Stadium.
After a blistering start, in which the Kiwis scored 22 points in as many minutes, Samoa rallied and reduced the score to just six points with four tries in quick succession.
New Zealand were able to move up a gear and see the game off, but not before Sonny Bill Williams managed his epic blunder.
After racing through, the rugby legend - vying to be the first man to win the World Cup in both Union and League - was clear in the in-goal area.
All he needed to do was ground the ball, but the complacent Sydney Roosters man slipped and put his foot into touch just as he attempted to score the try.
With England slipping to defeat in their first fixture of the World Cup against favourites Australia, it is now likely that Steve McNamara's side will face the Kiwis in the knock-out rounds.