Kieron Pollard blasted 102 from just 70 deliveries to lead the West Indies to an emphatic win over Australia in their fourth one-day international in St Lucia on Friday.
Victory meant the hosts went 2-1 up in the series with one match left to play.
Pollard destroyed Australia's bowling attack to rescue his team from an early batting slump and post a formidable total of 294 for seven.
The Australians, who won the toss but surprisingly elected to give the home side first use of a perfect batting pitch, scored 252 in reply, losing by 42 runs, as the West Indies polished them off in the 47th over.
"To play a match-winning knock feels great," said Pollard, whose spectacular innings featured five boundaries and eight sixes.
"Some of the sixes I didn't middle but once they get over the line they're all six."
Andre Russell (34) and captain Darren Sammy (31 not out) also chipped in at the end to help push the West Indies total towards 300.
With Pollard they piled on 117 runs in the last 10 overs, including 23 off the last over from Australian fast bowler Brett Lee, who finished with two for 72.
"It was the kind of total we could defend. The pitch was fantastic," Sammy said.
"We're looking forward to the final game. It would be good if we could get a series win."
After losing the first game by 64 runs, West Indies won the second by five wickets and tied the third. Sunday's final fixture is also in St Lucia.
Lee made amends for his expensive bowling by top scoring for Australia with 59 off 48 balls while David Hussey (57) also contributed.
However, the visitors were always struggling to reach their daunting target after four of their first five batsmen were dismissed in the 20s after making starts.
"Unfortunately, at the top of the order, me and David Warner haven't been able to bat on deep into the innings, I think that would have made chasing a bit easier," Australia skipper Shane Watson said.
"It was a beautiful wicket, like those at home. The St Lucia crowd saw a good game from West Indies, but unfortunately not from us."
J. Charles c Lee b Doherty 37
A. Barath c Wade b McKay 41
M. Samuels c Wade b Lee 11
Darren Bravo c D. Hussey b Watson 25
Dwayne Bravo lbw b Doherty 0
K. Pollard c M. Hussey b Lee 102
A. Russell c Bailey b Watson 34
D. Sammy not out 31
C. Baugh not out 0
Extras: (lb-3, w-10) 13
Total: (for seven wickets, 50 overs) 294
Did not bat: S. Narine, K. Roach
Fall of wickets: 1-56, 2-83, 3-106, 4-106, 5-146, 6-240, 7-728.
Bowling: Lee 10-0-72-2 (w-2), Hilfenhaus 10-1-43-0 (w-5), McKay 10-1-57-1 (w-2), Watson 10-0-55-2 (w-1), Doherty 10-1-64-2
S. Watson c Roach b Sammy 28
D. Warner c Narine b Dwayne Bravo 1
P. Forrest c Charles b Sammy 24
G. Bailey c Baugh b Russell 25
M. Hussey c Baugh b Russell 26
D. Hussey b Roach 57
M. Wade c Russell b Pollard 15
B. Lee c sub (Mathurin) b Roach 59
C. McKay c Pollard b Dwayne Bravo 2
X. Doherty c Sammy b Narine 1
B. Hilfenhaus not out 0
Extras: (lb-1, w-11, nb-2) 14
Total: (all out, 46.3 overs) 252
Fall of wickets: 1-3, 2-56, 3-62, 4-111, 5-112, 6-179, 7-196, 8-235, 9-250, 10-252.
Bowling: Roach 9.3-0-74-2 (nb-1 w-3), Dwayne Bravo 6-0-47-2 (w-5), Narine 10-0-21-1 (w-1), Sammy 9-0-42-2 (nb-1), Russell 7-0-34-2 (w-1), Samuels 3-0-17-0 (w-1), Pollard 2-0-16-1
Result: West Indies won by 42 runs to lead series 2-1.
Man of the match: Kieron Pollard