No one really has a clue how Tests in the UAE go. "Slow burners" seemed to be the conclusion last week. Win the toss, bat first, put up a big score, and dominate.

Nathan Lyon made a mockery of that formula in Abu Dhabi this morning, shredding his way through Pakistan's middle order and turning conventional wisdom on its head. Just after Pakistan had recovered from the loss of an early wicket and begun to put on a partnership that would reset them on course came a spell any grand old Asian spin master would remember in the rocking chair decades on.

Spread across two overs, he took four wickets in six balls as Pakistan tumbled from the relative affluence of 57 for one to the penury of 57 for five within 10 minutes. It didn't only tear up the narrative of the opening session, it may yet be the defining period of this Test series.

If it is not, that would be single-handedly down to one partnership, the one that came right after the carnage. Debutant Fakhar and a rejuvenated Sarfraz added 147 to lift Pakistan from the doldrums and carry them through to a relatively respectable 282. At the end of their careers, this innings is likely to rank near the top, and yet both were denied richly-deserved hundreds. Each fell for 94, ensuring that despite their brilliance, the day ended with honours even.

Pakistan finished on a high, though, landing a significant blow to the visitors late on, a diving catch from - who else - Sarfraz dismissing last game's hero Usman Khawaja cheaply. The icing on the cake was Mohammad Abbas trapping nightwatchman Peter Siddle in front middle and leg off the last ball.

For a man who had averaged almost 85 in the UAE previously, there was no foreshadowing what Lyon was about to produce. The second wicket partnership had accumulated 52 hard-fought runs, but Azhar Ali - struggling for form of late - chose unwisely to attack Lyon by charging down the wicket, only to scoop the ball straight into the bowler's hands.

That opened the floodgates. Haris Sohail couldn't keep the first ball he faced down and Travis Head at silly point caught sharply. An over later, Lyon struck two more bruising blows to the solar plexus of the batting order, sending Asad Shafiq and Babar Azam on their way. Babar's dismissal could most kindly be described as a brain-freeze, with the youngster charging down the track off just his second delivery, hopelessly beaten by both flight and turn.

The rejuvenation of Sarfraz was the defining narrative for Pakistan on the day. Gone was the uncertain, fidgety man apprehensive of going out to bat, and back came the street-smart cricketer who had risen through the ranks four years ago. Sarfraz the counter-puncher strode to the crease a few minutes short of the lunch break while Pakistani batsmen fell over themselves in a hurry to return to the pavilion. And what did he do? He counter-punched.

It was like a return to the halcyon days of 2014-15 for the Pakistan batsmen. Straight after lunch, he took the attack to Lyon, dancing down the track and carting him over midwicket. "I am in control," he seemed to be saying at a moment when his grip over the Pakistan team has never seemed weaker. This from a man who had only managed to pass 20 in an innings just once since middle order rocks Misbah-ul-Haq and Younis Khan retired 18 months ago.

Fakhar seems to have adapted to Test cricket with the same effortlessness as he did ODI cricket a year earlier, and would be desperately disappointed to miss out on a debut hundred. Sarfraz and Fakhar approached what was a dire situation in a delightfully insouciant way, Sarfraz finding the gaps as only a man of his wile can.

He manufactured strokes off both front and back foot to keep the scoreboard ticking over. He took up various positions in his crease to put Lyon off, and kept coming down the ground to ensure the runs didn't dry up. For the first hour after lunch Pakistan were especially fluent, thanks to their captain, while Fakhar, who had held up his end manfully before lunch, had the awareness to take a backseat in the period Sarfraz was most free-flowing.

After that partnership broke, Sarfraz began to noticeably tire as his first Test hundred in three years drew close. A blow on the left elbow by Mitchell Starc didn't help, with the captain requiring lengthy treatment. All of the day's events finally took their toll when, six runs away from the milestone, he tried to launch Labuschagne into the stands. It was a tired shot, and barely cleared the infield, with Peter Siddle holding onto the leading edge at mid-off.

Australia had gotten off to the perfect start with a stunning, if fortuitous, catch from Labuschagne to account for Mohammad Hafeez. It thudded into his groin at short leg, but Labuschagne managed to keep his wits about him and the ball off the ground, getting Australia off to the perfect start. It began what proved a particularly fruitful day for him; the part-time legspinner claimed three wickets, including the one that dismissed Fakhar to break his stand with Sarfraz.

On a day that ebbed and flowed, it was two spells of magnificence that came to shape the first day of this Test. One lasted six balls, the other 37 overs. It remains impossible to say which will play a bigger part in determining the destination of the series trophy.