That left Brisbane chasing a victory target of 209 but they were skittled out for 152 within 18 overs.
The 28-year-old hit 82 to lay the foundations for his side to reach a formidable victory target of 274.
Stephen Moore (60), Ashwell Prince (85) and Steven Croft all hit half-centuries as Lancashire cruised to their victory target of 219 with 4.2 overs to spare.
Chasing a relatively modest victory target of 213, Australia reached 217-4 to haul in the target off just 31 overs.
He was dropped by Rob Nicol but West Indies' march was relentless, Smith hitting the winning runs as West Indies comfortably reached their victory target of 136.
The strugglers took the last three wickets for four runs in the space of 38 balls as Middlesex failed to chase down a victory target of 118.
Ireland needed to avoid defeat on Sunday but, despite Porterfield recording a century at Adelaide, Pakistan chased down a victory target of 238 with seven wickets and 23 balls to spare.
Set a monstrous victory target of 413, Australia's chances of a virtually impossible win faded quickly when they were 25-3 at stumps on Friday when a phenomenal 21 wickets fell on a typically dry Galle wicket.
Asghar Stanikzai's men chased down a victory target of 117 with 12 balls to spare to claim their second Group B triumph and condemn Hong Kong to an early exit.
Sussex were left with a victory target of only 91 after Magoffin had removed Alfonso Thomas and Jamie Overton, with Chris Jordan adding the wicket of Peter Trego as Somerset could add only 12 to their overnight score.
Chasing a victory target of 143, Worcestershire looked to have blown their chances when they lost quick wickets and slipped to 112 for seven with three overs to go.
