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, despite Ian Bell's fourth-successive Test 50.

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 Bell (53), still batting down at number six after his increasingly impressive run of form, could withstand Johnson for long as England conceded a first-innings deficit of 81 by tea on day two.

Johnson's intervention came in the nick of time for Australia, after England had moved 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 - where Michael Hussey took a neat low catch.

After Johnson's next over from the Prindiville Stand end, Jonathan Trott and Kevin Pietersen were also gone - for four runs between them. Devilish inswing accounted for two lbws as both batsmen shaped to drive.

Australia missed an opportunity when Andrew Strauss (52) edged Ryan Harris between a static wicketkeeper and first slip for four when he had just 16. The England captain played and missed several times but also counted eight boundaries in a 95-ball half-century.

But, with Johnson in full cry, Harris (three for 59) got his man caught behind before lunch with a delivery which did not swing but brought a deserved outcome for the bowler's perseverance. Johnson soon made Paul Collingwood his fourth victim, and 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 by Ricky Ponting 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 it was no surprise that Johnson made quick work of the final two wickets as the last four fell for just six runs.