Hussey's 68 not out helped Australia to reach 215 for six and a 3-0 lead in the best-of-seven series, after it had appeared they would fail to achieve the target when Paul Collingwood captured two quick wickets to leave Australia floundering at 100 for five.
The 33-year-old Hussey, younger brother of injured batsman Mike Hussey, steadied the innings with Steve Smith (26) and then John Hastings (18 not out), who cut Chris Tremlett to deep backward point for the two runs needed for the win.
Brad Haddin had held the top of the innings together with an aggressive 54, though the other top-five batsmen failed to make it into double figures.
Jonathan Trott (84 not out) had anchored England's score of 214, though he failed to take advantage of the powerplay in the final overs when he was batting with the tail and seemed content to push for singles rather than chance his arm despite only three players being allowed outside the fielding circle.
England were again guilty of failing to bat out their full complement of overs. Chris Tremlett (1) was run out on the final ball of the 48th over when he failed to ground his bat, which denied Trott the possibility of a last flurry.
Trott shared in a 57-run partnership with Eoin Morgan (30) and 49 runs with Luke Wright (32) but too many of England's batsmen threw their wickets away with loose shots. Brett Lee took three for 27 and was named man of the match.
Score Board
ENGLAND
Strauss (run out) 23
Prior lbw Lee 0
Trott (not out) 84
Bell c&b Watson 10
Morgan c Clarke b D Hussey 30
Collingwood b Doherty 1
Yardy c&b Doherty 7
Wright c Haddin b Hastings 32
Woakes c Haddin b Lee 12
Shahzad c White b Lee 4
Tremlett (run out) 1
Extras (LB-3, W-6, NB-1) 10
Total (all out, 48 overs) 214
Fall of wickets: 1-1, 2-38, 3-61, 4-118, 5-119, 6-130, 7-179, 8-199, 9-208.
Bowling: Lee 8-0-27-3; Bollinger 8-0-36-0; Hastings 10-0-51-1; Watson 6-0-17-1; Smith 3-0-19-0; Doherty 10-0-37-2; D Hussey 3-0-24-1.
AUSTRALIA
Watson b Tremlett 9
Haddin c Woakes b Collingwood 54
Marsh lbw Shahzad 6
Clarke c Yardy b Woakes 9
White lbw Collingwood 7
D Hussey (not out) 68
Smith c Yardy b Tremlett 26
Hastings (not out) 18
Extras (LB-7, W-11) 18
Total (for 6 wkts, 46 overs) 215
Fall of wickets: 1-10, 2-27, 3-59, 4-92, 5-100, 6-163.
Bowling: Shahzad 10-0-45-1, Tremlett 9-0-50-2, Woakes 7-0-31-1, Wright 2-0-12-0, Yardy 10-0-45-0, Collingwood 8-0-25-2.