MITCHELL Johnson's devastating spell of four wickets for seven runs did the principal damage as England were bowled out for only 187 at the WACA.

Johnson (six for 38) undermined England's ambitions of retaining the Ashes in this third Test with a supreme exhibition of late swing and left-arm pace. Only Ian Bell (53), still batting down at number six on his way to his fourth successive Test half-century, could withstand Johnson for long as England conceded a first-innings deficit of 81 by tea on day two.

Australia then sought to consolidate their advantage but lost opener Phil Hughes and captain Ricky Ponting cheaply to Steven Finn to leave them at 34 for two. Vice-captain Michael Clarke was next to go with the score at 64 for three but the hosts suffered no further losses, with opener Shane Watson reaching his half-century, to close the day in a dominant position on 119 for three, 200 runs ahead.

Johnson's intervention came in the nick of time for Australia, England losing all 10 wickets in only 38 overs - after progressing serenely to 78 without loss on another sunny morning.

He broke the opening stand when Alastair Cook fell for his first score under 50 so far in the series, a push-drive sliding off the face of the bat low to gully. After Johnson's next over from the Prindiville Stand end, Jonathan Trott and Kevin Pietersen were also gone - for four runs between them.

Ryan Harris (three for 59) removed captain Andrew Strauss (52) and Johnson soon made Paul Collingwood his fourth victim, the third to go lbw to inswing.

Matt Prior and Graeme Swann each dug in after lunch to lend Bell valuable support.

Peter Siddle was detailed to bounce out the next wicket - and the tactic eventually worked when Prior tried to ride the bounce but unluckily deflected the ball down on to the base of his leg stump, via his hip. Swann refused to give in during an unequal struggle, until the return of Harris saw him off - caught behind, pushing forward.

The classy Bell had barely put a foot wrong and brought up his 79-ball 50 with an appropriately commanding punch on the up past cover off Harris for his sixth boundary. With the tail exposed, though, he edged an attempted drive at the same bowler high to Ponting at third slip, and the hosts wasted no time picking up the final two wickets.

Hughes, Ponting and Clarke all fell cheaply when Australia started their second innings, but Watson (61 not out) and Michael Hussey (24no) steadied the ship with a composed partnership, both dealing well with the introduction of Swann to the attack, with the former going on to reach his half-century from exactly 100 balls.