England captain Alastair Cook won the toss in overcast conditions that promised to assist swing and seam bowling and saw his decision vindicated in the most dramatic style imaginable, with pace-man Broad taking two wickets in the first over of the match.
Read: Cook urges his team to write their own Ashes history
Broad, leading the attack in the absence of injured James Anderson -- England's all-time leading wicket-taker -- needed just three balls on his Nottinghamshire home ground to take his 300th Test wicket when opener Chris Rodgers, on nought, edged to Cook at first slip.
It was the first duck of Rogers's 46-innings career in Test cricket.
Four balls after becoming just the fifth England bowler after Anderson, Ian Botham, Bob Willis and the late Fred Trueman to take 300 Test wickets, Broad struck again.
Top-order batsman Shaun Marsh, brought in to replace dropped younger brother Mitchell, also fell for a duck when he was caught in the slips by Ian Bell off Broad.
And the 29-year-old Broad then had Adam Voges (one) brilliantly caught one-handed by diving fifth slip Ben Stokes to leave Australia 21 for five in the fifth over.
Australia captain Michael Clarke's desperate run of form continued when, driving loosely outside off stump against Broad, he was well caught by a leaping Cook at first slip to leave the tourists 29 for six.
Read: Michael Clarke: I won't quit
The 34-year-old Clarke's exit meant one of the best batsmen of his generation had now managed just 104 runs in seven innings this series at an average of 17.
Broad, the son of Ashes-winning former England batsman Chris Broad, had taken five wickets for six runs in 19 balls.
Australia, once more ruthlessly exposed by the moving ball, were now an astounding 33 for seven in 9.2 overs.
Broad then removed Mitchell Starc (one) and Mitchell Johnson (13) with the aid of slip catches by Root to reduce Australia to 47 for nine in 13 overs.
Mitchell Johnson (13) and Australia captain Michael Clarke (10) were the only batsmen to make double-figure scores in an innings that was wrapped up in just 18.3 overs -- the quickest any team has ever been bowled out in the first innings of a Test -- during a scarcely believable 94 minutes' play in Nottingham.
Australia's total -- with extras the top score on 14 -- was the lowest by either side in an Ashes innings since England were dismissed for 52 at The Oval in 1948.
"It's pretty unbelievable. It's not sunk in," Broad told Sky Sports after drawing level with England great Fred Trueman's career tally of 307 Test wickets.
"We knew Trent Bridge would offer us something but we had to bowl well and take our catches.
"It was unbelievable. We've given ourselves a chance to get a big lead now. We just have to graft hard."
At lunch, England were 13 without loss. Adam Lyth was eight not out and Alastair Cook, the England captain, four not out.
England lead the five-match series 2-1 and victory at Trent Bridge would see them regain the Ashes.
Read: The 2015 Ashes story so far
England bowlers with 300 Test wickets (wickets, matches, bowler)
413 (107) - James Anderson
383 (102) - Ian Botham
325 (90) - Bob Willis
307 (67) - Fred Trueman
307 (83) - Stuart Broad
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