Fifth ODI, Trinidad. West Indies 290-5 (50 overs) bt Australia 251 (50 overs) by 39 runs
Lara's 80 helped steer the Windies to victory
The West Indies have ended Australia's 21-match winning streak with a 39-run victory at Queen's Park Oval.
The Aussies had taken an unassailable 4-0 lead in the best-of-seven series on Saturday.
But on Sunday the world champions' batting line-up capitulated, Andrew Symonds the only antipodean starring with the bat with 77 off 85 balls.
Earlier Wavell Hinds (79) and Brian Lara (80) put on 178 runs for the second wicket, before Mervyn Dillon was the Windies' leading wicket-taker with three scalps.
The result halted the Caribbean side from suffering a 12th successive defeat to Australia.
Afterwards Lara said: "It was a great team performance, we got a good total, myself
and Wavell batted very well and set up the game for [Ramnaresh] Sarwan and [Marlon} Samuels and we bowled really tight, all credit must go to the team."
The West Indies' hopes of achieving a consolation win in the series were given a boost when they achieved the third-best score ever made at the Queen's Park Oval after Lara won the toss and elected to bat.
Ramnaresh Sarwan scrambles for safety during his 32
Full credit to the West Indies today, they played really well
After Chris Gayle's early demise, the first of Brett Lee's three victims, Lara joined Hinds at the crease.
The pair gave the likes of Andy Bichel, Nathan Hauritz and Michael Clarke scant respect with some audacious strokeplay.
Bichel finally removed both men but his 10 overs cost 67.
Lee added the scalps of Sarwan and Samuels before the end of the innings.
In the dead rubber, Australia's early batting order collapsed. And Adam Gilchrist, Jimmy Maher and captain Ricky Ponting were all back in the pavilion with the score on 57.
Symonds added some respite from the Windies bowling attack but only Michael Clarke (39) and Michael Bevan (31) were able to keep him company.
When Clarke was removed by Dillon, the second of his three victims, and Symonds was bowled by Samuels, Australia's challenge was effectively over.
Ponting was full of praise for the Windies after the defeat.
He said: "Full credit to the West Indies today, they played really well, they batted well and then took three early wickets with the new ball where probably the game changed."
There are just two games remaining of the series in Grenada - on Friday and on Sunday.
West Indies: CH Gayle, WW Hinds, RR Sarwan, BC Lara (capt), MN Samuels, RL Powell, RO Hurley, RD Jacobs (wkt), DE Bernard, M Dillon, CD Collymore.
Australia: AC Gilchrist (wkt), JP Maher, RT Ponting (capt), A Symonds, MJ Clarke, MG Bevan, IJ Harvey, AJ Bichel, B Lee, GD McGrath, NM Hauritz.