BBC News 24's Darren Jordon reports

Gough's late-order treble came after a brilliant fourth wicket stand of 190 between Mark and Steve Waugh had threatened to end the contest on the very first day.

The Australians subsided from 284 for four to 322 all out as England produced a sensational fightback with the new ball.

The last five wickets fell for just three runs thanks to Gough's inspired spell and another penetrative performance from Dean Headley.

Aussies' family affair

Jonathan Agnew: "Australia's remarkable collapse" (BBC Radio 5 Live)

Earlier the Waugh brothers, who came together with the home side struggling on 52-3 after winning the toss and electing to bat, seemed to have turned the match decisively in Australia's favour.

Mark Waugh smacked his 16th Test century and brother Steve was out for 96 - the ninth time he has been dismissed in the 90s, which is a new Test record.

Mark Waugh salutes his home crowd after a superb ton

The tormenting twins took the game to England with an emphatic display of batting in the afternoon, full of sumptuous stroke-play.

But the abiding memory of the day will be Gough's inspired spell just before the close.

First Ian Healy diverted a snorter to wicket-keeper Warren Hegg and the very next ball Stuart MacGill had his middle stump removed by another deadly delivery.

Mark Waugh: "There's a bit there for the fast bowlers" (BBC Radio 5 Live)

But the best was saved for last as Gough ripped out Colin Miller's off-stump with an in-swinging yorker to complete the hat-trick.

The wicket sparked delirious scenes at the SCG as the England team swamped the Yorkshire paceman, who was greeted to a standing ovation by an enormous crowd of 42,000.

Deano does it again

But Gough's headline-grabbing efforts should not overshadow Headley's contribution.

Dean Headley dismisses Mark Taylor for the first wicket of the day

The Kent seamer, who bowled England to victory in the third Test in Melbourne, was again the pick of the attack.

He saw off both openers in the morning, then sparked the evening collapse with the dismissal of Mark Waugh for 121 and then wrapped up the innings with the wicket of Glenn McGrath - his fourth of the day.

The whole tone of the match changed in rollercoaster fashion just as play was drawing to a close.

Waugh-weary England struggle in afternoon

It had all looked so different at the start of the evening session, when the Waughs were rampaging on their home ground and Australia were in total control at 242-3.

Steve Waugh shows his disappointment

But their partnership was finally ended on 190 by Peter Such, who dismissed Steve Waugh as the in-form batsman scented his third century of the series.

Such tempted him down the wicket and bowled him through the gate for 96 - but by then the damage had been done.

The Waughs had come together after an hour's play with Australia struggling at 52-3, after Headley and Tudor had given England the perfect start.

Headley, who bowled England to victory at Melbourne in the fourth Test, struck in the fourth over of the day, when Mark Taylor edged low to Graeme Hick in the slips for two.

And his inspired spell received a second reward, when Michael Slater was tempted into a hook shot and gloved the ball to Hegg for 18.

That left the score 52-2 and without a run being added, Justin Langer, who had suffered two major scares on his way to 26, cut a wide delivery from Tudor and Ramprakash claimed a comfortable catch at square leg.

With any early movement disappearing from the pitch as the afternoon wore on, the Waughs, revelling in the conditions on their home ground, tormented England's weary bowlers with a succession of sumptuous strokes. But once Steve Waugh had gone, Darren Lehmann perished to an instinctive catch from Nasser Hussain off Tudor after a quickfire 32.

The dismissal of Mark Waugh then exposed the tail - and Gough was able to take advantage, to devastating effect.

Atherton forced out

Before play had even begun England had received an 11th hour blow to their hopes of levelling the series when Atherton was forced out with a recurrence of his long-term back injury.

His late withdrawal brought about a dramatic recall for Mark Butcher, who had been left out of the side on Friday.

Left-arm paceman Alan Mullally was dropped - possibly amid fears he could rough up the pitch and aid the opposition spinners - in favour of youngster Tudor.

England opted for just one specialist spinner, with Such edging out late call-up Ashley Giles, while Australia went into the match with three slow bowlers - Miller, MacGill and the fit-again Shane Warne.

Australia lead the series 2-1 and have already retained the Ashes - but victory at the SCG would give England an unlikely share of the honours.

Scorecard - Close:

Australia first innings:
M Taylor c Hick b Headley 2
M Slater c Hegg b Headley 18
J Langer c Ramprakash b Tudor 26
M Waugh c Hegg b Headley 121
S Waugh b Such 96
D Lehmann c Hussain b Tudor 32
I Healy c Hegg b Gough 14
S Warne not out 2
S MacGill b Gough 0
C Miller b Gough 0
G McGrath c Hick b Headley 0

Extras 11
Total (all out, 87.3 overs) 322

Fall: 1-4, 2-52, 3-52, 4-242, 5-284, 6-319, 7-321, 8-321, 9-321

Bowling: Gough 17-3-61-3, Headley 19.3-3-62-4, Tudor 12-1-64-2, Such 24-6-77-1, Ramprakash 15-0-56-0

England : A Stewart (captain), M Butcher, N Hussain, M Ramprakash, J Crawley, G Hick, W Hegg, D Headley, D Gough, A Tudor, P Such.