Second Test, Headingley: Pakistan 148-3 v Australia 88
Live commentary on Test Match Special and Radio Five Sports Extra, scorecards on BBC website, live on Sky Sports
North is the sixth Australia wicket to fall as Kamran Akmal holds the catch
Salman Butt enjoyed a dream first day at the helm as Pakistan built a 60-run lead after bowling out Australia for 88 on the opening day of the final Test.
Australia chose to bat but were 41-5 by the 17th over as Pakistan's three main seamers extracted prodigious movement.
Teenage left-armer Mohammad Aamer took 3-20 and Mohammad Asif 3-30, with Tim Paine last out having top scored on 17.
Butt shared an opening stand of 80 with Imran Farhat in reply as his side made 148-3 before bad light curtailed play.
Australia are 1-0 up in the two-match series and few could have expected their lowest Test total since 1984.
There had been over two inches of rain in Leeds overnight and overcast skies gave even greater incentive for the bowlers, but Australia captain Ricky Ponting opted to bat first.
Indeed Ponting has not asked a team to bat first since the Ashes series of 2005 at Edgbaston when England amassed 400 on the first day.
The opening six overs produced little threat to the batsmen but then the Pakistan seamers began to find their line, and accompanied the accuracy with some stunning movement in the air and off the pitch.
Smith had no answer to a stunning Aamer burst immediately after lunch
Simon Katich was the first of five wickets inside 11 overs, trapped lbw having moved too far across, while Shane Watson was plumb lbw to one from Mohammad Asif that swung back in sharply.
Michael Clarke was fortunate not to have been out lbw on three but did not add any further runs when he was beaten by Umar Gul, who had swung several deliveries away before he nipped one back to move through the gate.
Ponting will perhaps never have made a scratchier six, from 21 balls, and was lbw after losing his balance trying to play across his pad.
The expected fightback was simply not allowed to happen, Pakistan aware that a full ball would zip through with swing and seam but a short one would lose pace and effectiveness.
One man who might have helped Australia out of the mire was Mike Hussey but he was unluckily given out lbw when one from Gul appeared to be doing too much and heading down the leg-side.
Butt's hunch to try the medium pace of Umar Amin was rewarded when more swing found the edge of Marcus North's bat to give the 20-year-old a maiden Test wicket.
It was 73-6 at lunch but lingering hopes of a recovery were swiftly ended with the first two balls of the afternoon session by the impressive 18-year-old Aamer.
The ball certainly swung around, we were not good enough to stop the rot
First he breached Steve Smith's defences and then produced an even better one that swung dramatically away from left-hander Mitchell Johnson and crashed into the timbers.
The innings quickly subsided but thoughts that the Pakistan innings would follow a similar pattern were soon averted.
There were some excellent deliveries but the Australian bowlers were not able to produce them as consistently as their opponents had done.
The Pakistan batting was also commendably disciplined, Butt finally undone by some late swing from Ben Hilfenhaus as a full delivery crashed into the stumps.
Australia took two more wickets but with dark clouds gathering and causing the light to deteriorate rapidly Ponting turned to leg-spinner Smith, whose second ball was smashed for six by Umar Akmal as Pakistan continued their domination.
As he reflects on a torturous day, the Australia skipper may choose to look back to January this year at Sydney, when he decided to bat first, his team were all out for 127 but went on the win that match.
Australia coach Tim Nielsen admitted his side's performance was poor and said: "When you walk off and you have 88 next to 11 batsmen it's not a good enough total. We never got a smell of getting a partnership going.
"We were surprised to see how dry the wicket was this morning, we thought it was going to be hard against the new ball but would then flatten out to be a nice batting wicket.
"Pakistan bowled beautifully, hit the wicket hard and didn't just expect the conditions to do it for them. The ball certainly swung around, we were not good enough to stop the rot."
Gul, who captured 2-16, said of Ponting's decision to bat first: "There was moisture under the wicket so I think it was a shocking decision, especially for Australia.
"I don't know what the captain and coach's decision was going to be but if we won the toss we (the Pakistan bowlers) were ready to bowl first.
"When the clouds come it starts swinging and when the sun comes it is a bit flat and good for the batsmen. It all depends on the clouds when you can get some swing and seam.
"It was a good day for us. The bowlers did very well. Aamer, Asif and myself did very well as we planned before the game.
"We are planning to put on another 150 to lead by around 200. We need to bat well to get that and then we will have a good chance."