England require 224 to reach a first World Cup final in 27 years after a polished and occasionally hostile bowling display rattled Australia – though Steve Smith's defiance carried them to a respectable total.
The defending champions had teetered to 14 for three after deciding to bat first, England exploiting the early seam movement on offer at Edgbaston, before Jofra Archer bloodied Alex Carey's jaw with a vicious bumper.
Carey went on to put on 103 alongside Smith, who rarely thrilled in his 85 from 119 balls but his tournament best innings helped Australia to 223 all out in 49 overs as they bid to extend their unbeaten sequence in World Cup semi-finals.
Smith, booed to and from the crease, held Australia's innings together and gave them a fighting chance of reaching this Sunday's showpiece against New Zealand – which would be a re-match of the 2015 final.
Chris Woakes and Adil Rashid each rose to the occasion with three wickets apiece as they attempt to win a knockout match in this tournament for the first time since 1992.
It was Archer who set the tempo with the initial breakthrough, removing Australia captain and dangerman Aaron Finch, who registered a century against the hosts in their group meeting at Lord's last month.
Finch's decision to assert scoreboard pressure after winning the toss – in a tournament where batting first has often been an advantage – looked to have backfired when he and Warner were sent packing within the first 16 deliveries.
Finch was pinned in front first ball, burning a review in the process, before Warner fended to second slip after being taken aback by extra bounce from Woakes, who castled Pete Handscomb with a nip-backer via an inside edge.
Every ball was an event at this stage and Carey looked to be in some strife when his helmet was dislodged by Archer's brutal bouncer. Australia's wicketkeeper-batsman did well to catch the helmet before it potentially bounced on to his stumps.
Carey had his chin bandaged – he would later have stitches and Cricket Australia confirmed he will be fine to keep wicket – before resolutely steadying the ship alongside Smith.
Their century stand lacked fireworks but allowed Australia to recover from a dreadful start, and they were only parted when Carey, on 46 holed out to deep midwicket off Adil Rashid.
That wicket seemed to galvanise England's premier leg-spinner, whose googly sent Marcus Stoinis packing second ball as Australia lurched to 118 for five.
Glenn Maxwell's punchy 22 was ended when he tamely poked an Archer slower ball to Eoin Morgan at short cover while Pat Cummins nicked to slip off Rashid from one that moved away from him.
Steve Smith survived an lbw review off Mark Wood, Hawkeye revealing the ball would have only clipped the top of the stumps, but the former Australia captain was sent packing shortly afterwards.
Jos Buttler removed his keeping glove and threw down the stumps at the non-striker's end, Smith short of his ground and already walking back to the pavilion before the replays were shown.
Smith's departure was the start of Australia losing their last three wickets in the space of 12 balls, Woakes finishing as the pick of the bowlers with three for 20.
