Close Australia 253 (Katich 80, Aamer 4-72) and 100 for 4 (Katich 49*) lead Pakistan 148 (Butt 63, Watson 5-40) by 205 runs
Scorecard and ball-by-ball details

Another breathless day of Test cricket at Lord's finished with Australia in command thanks to the unlikely bowling exploits of their five-wicket hero, Shane Watson, but with Pakistan clawing back their lost ground courtesy of Mohammad Asif and Umar Gul, who found inspiration late in the day to claim four quick wickets in 10.1 overs. By the close, Australia had extended their 105-run lead by a further 100, with Simon Katich once again the linchpin of their batting, as he nudged along to 49 not out, to add to his invaluable first-innings 80.

With 15 wickets falling on the second day, to go with the nine that Pakistan claimed on day one, the prospect of a three-day finish cannot be ruled out, especially if the weather remains as overcast and seam-friendly as it has been so far. And with that in mind, Katich's calm contributions are likely to prove to be the difference between the sides in the final analysis. But the stand-out performance on the second day was that of his opening partner Watson, whose second string surged to the fore as he claimed not only his first five-wicket haul in Test cricket, but became the first man to inscribe his name on the newly unveiled neutral honours board in the away dressing-room.

Bowling with a hint of movement on a nagging wicket-to-wicket length, Watson ripped through Pakistan's lower middle-order after Ben Hilfenhaus had prised open the top, with only Salman Butt and Shahid Afridi providing any measure of resistance, albeit in dramatically differing styles. Butt picked his shots wisely to top-score with 63, while the captain Afridi marked his first Test for four years with a bedlamic 31 from 15 balls. But Watson did for both in a remarkable 7.5-over spell, to leave Australia's first-innings 253 looking like a formidable total.

With heavy cloud cover and a regular threat of rain, the conditions were once again perfect for seam and swing bowling, although it took a few exploratory overs with the new ball before Ricky Ponting found the right ends to suit the respective merits of his bowlers. Having started his work from the Pavilion End, Hilfenhaus switched to the Nursery after two overs and made an instant impact as he nipped an off-stump delivery up the slope to snag the edge of Imran Farhat's bat, for the wicketkeeper Tim Paine to collect the first catch of his Test career.

With the incision made, Australia scarcely looked back. Butt guarded his off stump with diligent strides down the pitch while cashing in on regular width to crash 12 fours, the vast majority through the arc between third man and extra cover. But without the legendary middle-order stalwarts, Mohammad Yousuf and Younis Khan, the rest of the side lacked the experience to master the conditions, and were duly scythed down by the Aussie seamers.

Azhar Ali was the first of two debutants to have his mettle tested. He got off the mark with a second-ball single through the covers, and picked off two fours behind square on the off and leg side as he pursued a safety-first approach in his maiden innings. But with five minutes to go until lunch, Hilfenhaus beat him with some extra lift outside off, and Paine was on hand to claim his second victim.

Umar Ali replaced him at No. 4, and having waited for the entire lunch break to face his first ball in Test cricket, which was dabbed to fine leg for a single, he was then made to wait a further 50 minutes for his second, as the umpires took the players off for bad light after a single over of the session. When play eventually resumed, Umar lasted just two more deliveries, as Mitchell Johnson grazed his edge with an off-stump lifter, to bring to an end one of the more staccato debuts of recent times.

Thereafter it was all about Watson, who was thrown the ball after six overs of resistance from Butt and Umar Akmal, and struck in his first over as Akmal completely misjudged a straight delivery and was nailed plumb lbw for 5. In Watson's next over, his brother Kamran Akmal fared even worse, as he inexplicably padded up on the line of middle stump, and was sent on his way for a duck.

At 83 for 5, the captain, Afridi responded as only he knows how, lashing four fours and two sixes from Watson's next ten deliveries, before aiming another massive mow across the line, and steepling a massive top-edge to Johnson at mid-on. He had gone for a crazy 31 from 15 balls, and when Mohammad Aamer poked Doug Bollinger to slip for a second-ball duck, Pakistan were in freefall at 117 for 7.

Gul followed suit three overs later as Bollinger switched his line to round the wicket, before Watson capped a remarkable session by swinging a yorker through Butt's hitherto obdurate defences. Five balls after tea, Danish Kaneria dabbed Watson to Steven Smith at third slip to complete an historic haul.

In reply, Pakistan were understandably lethargic with the ball, as Katich and Watson eased to an opening stand of 61 without really being forced to break sweat. But not for the first time in the match, Pakistan found a second wind through the efforts of Asif, who tempted Watson into a loose drive to first slip, whereupon Ponting - in possibly his final Test innings at Lord's - padded up to an inswinger, and was sent on his way for a sixth-ball duck.

The decision looked plumb to the naked eye, but replays suggested the ball might have slipped down the leg side. To add injury to insult, Ponting was then punched accidentally in the helmet by an exuberant Asif, who stretched back his arms at the precise moment that the captain was walking past. After his tangle with Aamer in the first innings, it was an unfortunately timed incident, but no malice was intended.

Gul, however, had malice aforethought in a superb final spell that left Australia very grateful for the bad light that eventually closed in with five minutes of play remaining. First he plucked out Michael Clarke's off stump with a perfect offcutting seamer, then one ball later, he dislodged Mike Hussey for a duck as he zipped a low edge to first slip. But Johnson joined Katich to see out the final minutes, and restore some calm after a frenetic passage of play.

Andrew Miller is UK editor of Cricinfo.