Sydney - Australia suffered a chaotic run-out and were 77 for two in their second innings on Thursday as they struggled to avoid a huge defeat in the final Ashes Test against a rampant England.
Shane Watson became the third Australian opener run out in the series in a dreadful breakdown in communication with Phillip Hughes in the 13th over as Australia were confronted with a massive 364-run innings deficit.
England have already retained the Ashes at last week's fourth Melbourne Test and are chasing their first series victory in Australia for 24 years.
At tea, Australia were 77 for two, with acting captain Michael Clarke on 19 and debutant Usman Khawaja on four.
Australia's formidable task of saving the match was made that much more difficult by Watson's self-inflicted dismissal for 38 and came after Simon Katich was run out in the second Adelaide Test and Hughes at Melbourne.
Hughes worked the ball to midwicket for a leisurely single, but Watson turned and took off for a second run and continued on as Kevin Pietersen's throw came in with both batsmen stranded at the non-striker's end.
Hughes lasted just seven more overs before he fell for 13 in a familiar mode of dismissal, tickling outside offstump to a slanting Tim Bresnan delivery to the slips.
The New South Wales left-hander has scored a disappointing 108 runs in six innings since replacing the injured Katich after the second Test.
Earlier, Matt Prior became England's third centurion as the tourists posted their highest total of 644 in Australia and eclipsed the previous highest score of 636 at the SCG, set back in 1928-29.
It was also the fourth time England have passed 500 in the series.
It took Australia's bowlers 177.5 overs and 758 minutes to finally dislodge rampant England, who had three century-makers -- Alastair Cook (189), Prior (118) and Ian Bell (115).
Graeme Swann was left unbeaten on 36 off 26 balls as England frolicked along at 3.6 runs an over.
Prior, who was 54 overnight, took to the Australian attack and raised his fourth Test century with a four through the covers off spinner Michael Beer.
His 197-minute blitz was the fastest England Ashes century since Ian Botham in 1981.
The maligned Mitchell Johnson finished Australia's best bowler with 4-168 off 36 overs.