Smith, Harris star with ball for Australia
Surprise packet Steve Smith took three crucial wickets late on day one to revive Australia on day one of the second Test at Lord's.
A Peter Siddle no ball had earlier cost the tourists dearly, but Smith finished with 3-18 from six overs to tip the match back in Australia's favour.
At stumps England were 7-289, not ideal after winning the toss.
Smith's part-time leggies had yielded just four Test wickets leading into the match, but the 24-year-old answered an inspired call from captain Michael Clarke when his side were starting to slip.
Smith entered the attack with England 5-267 but an incredible 22-ball burst earned him figures of 3-12.
He also broke a 144-run partnership between Ian Bell (109) and Jonny Bairstow (67).
There was a slight downside to Smith's heroics - he may not have got a bowl in the first place if not for a left hip injury suffered by Ashton Agar (0-44), who received a come-down from the lofty heights of his debut at Trent Bridge.
However the teenager is expected to bat and bowl as required for the rest of the match.
Ryan Harris (3-43) fired out of the blocks to take three wickets to justify his recall to the Australian attack, but Siddle (0-53) undid a lot of the hard work by over-stepping when England were on the ropes.
Clarke's gut feeling was spot on all day and, when he threw the ball to Shane Watson (1-41) after just four overs of play, the man he's allegedly feuding with responded to his captain's show of faith by trapping Alastair Cook lbw.
In the next over, Harris removed Joe Root and Kevin Pietersen to leave England reeling at 3-28.
Harris, called in at the expense of Mitchell Starc, also had Jonathan Trott caught in the deep for 58 when the No.3 seemed destined for a big hundred.
England were in trouble and would have been on their knees had Siddle's front foot not allowed the home side an avenue back into the contest.
In the 50th over, Siddle crashed through the stumps of Bairstow with a brilliant delivery that would have left England at 5-171.
But as Bairstow was halfway to the pavilion, he was called back by umpire Kumar Dharmasena after replays showed the Victorian quick had overstepped the mark and bowled a no-ball.
Only millimetres in it, but the correct call was made.
The crucial Bairstow- Bell partnership went on to add 100 from the time of the Siddle reprieve until Smith was thrown into the attack in the 77th over.
After a full toss was smashed for four, Smith delivered a gem that spun and dipped to have Bell caught at slip by Clarke to end his third hundred from the past three Ashes Tests.
Smith wasn't content with Bell's wicket though, and got rid of Bairstow (67) caught and bowled, and Matt Prior caught behind.
Scoreboard at stumps on the opening day of the second Test between Australia and England at Lord's:
A COOK lbw Watson 12
J ROOT lbw Harris 6
J TROTT c Khawaja b Harris 58
K PIETERSEN c Haddin b Harris 2
I BELL c Clarke b Smith 109
J BAIRSTOW c & b Smith 67
M PRIOR c Haddin b Smith 6
T BRESNAN not out 7
J ANDERSON not out 4
Extras (11lb 3w 4nb) 18
Total (for seven wickets) 289
Fall: 18 (Cook), 26 (Root), 28 (Pietersen), 127 (Trott), 271 (Bell), 274 (Bairstow), 283 (Prior).
Bowling: J Pattinson 18-3-79-0 (3w 1nb), R Harris 20-6-43-3, S Watson 12-4-41-1, P Siddle 20-6-53-0 (1nb), A Agar 13-2-44-0 (2nb), S Smith 6-1-18-3.