It was the 131st over of the innings, the 41st of the day. Sajid Khan had bowled a tight couple of overs to Cameron Green, but it was really the left-hander Sajid was brought into the side to target. Never mind that Pakistan would have preferred this menace to make itself apparent in the 31st rather than the 131st over, and that the left-hander in question, Usman Khawaja, weren't batting on 160, having faced 367 balls and spent over nine hours in the searing dry Karachi heat.
But Sajid found some grip and turn, and Khawaja played inside the line. The second ball, there was drift in and spin out as the Australian opener found himself beaten all ends up, the ball fizzing past the outside edge and kissing off stump. Sajid allowed himself an extravagant celebration and the crowd, beaten down by the afternoon sun and an anodyne first session, roared into life. It was Pakistan's finest moment all day.
It may also be one that keeps them up at night.
There might have been some consternation at Australia's approach to the game post-tea, when, instead of pushing for quick runs and a crack at Pakistan in the setting sun, Alex Carey and Mitchell Starc decided instead to slow things down, almost to a grinding halt. They scored just 20 runs in the first 12 overs post-tea, with the spinners operating almost exclusively by now. Starc ended the day batting on 28 off 95 balls, his strike rate the lowest he's ever managed in an innings of 20 or more. And while the spectators, and perhaps even Pakistan, waited expectantly for the declaration, Pat Cummins was nowhere to be seen. Australia kept batting, and, under the blistering Karachi sun, Pakistan kept bowling.
Perhaps the tedium was the point on a pitch that was fairly slow, and against a Pakistan attack that was beginning to look enervated. Hasan Ali, who has only just returned from an adductor injury that kept him out of the first Test, saw his workload managed from time to time across both days, forcing Babar Azam to turn to Shaheen Shah Afridi for 30 overs in this innings. Sajid and Nauman Ali's workloads were even more onerous, the pair combining to send down 99 of the 180 overs sent down so far. Only once in Asia have Australia ever batted for longer.
Pakistan were being ground down slowly, every extra over a body blow. With the pitch increasingly showing signs that it will deteriorate in the coming days, Australia appeared to understand that there was no better time to bat than now, front-loading the runs before potentially having two full swings at Pakistan.
Carey, who fell seven short of a hundred, made that point at the end of the day's play. "We were clear [about our plans] going into last night. The captain basically said to the batters to get your head around batting all day unless the message comes otherwise. Starcy and I were just batting along, it's not the easiest wicket to score quickly on.
"I know that might sound interesting, but it's starting to be a little bit variable, inconsistent, there was reverse-swing at times throughout the day. The offspinner [Sajid], he bowls a lot of balls in a good area and with not a lot of pace on them. The more runs we can get in this first innings, it sets us up for the back end. But think the wicket is starting to show a little bit of life now, or the opposite, it's inconsistent, some patches are starting to open up a little. Think the game will move quicker going into the back end of tomorrow and day four and day five."
The temptation to view this Test as something of an extension of Rawalpindi as far as the pitch is concerned is a dangerous one to succumb to. Pakistan might have spent much of day two waiting for their turn to bat and expecting that they might be able to match the longevity of Australia's innings, but there was enough evidence to suggest this surface might gradually become less docile. The spin has become less predictable and more extravagant, and Hasan, when he bowled with the old ball, found reverse-swing that should perk Starc up when he has ball in hand. In batting all day, the visitors displayed a clarity of thought and planning not always apparent in their recent trips to Asia, where they have won just three Tests and lost 17 in the last 15 years.
"Reverse-swing is always difficult," Carey said. "Coming over from Australia we probably don't experience those conditions a lot but obviously the home team will have. That's the beauty of having Mitchell Starc in our side, 145 clicks with reverse-swing is going to be difficult. Pat Cummins is the same, and also Greeny. We've got some weapons there when the ball starts to reverse.
"[We're] super excited to see the two spinners, Nathan [Lyon] hits a beautiful area regularly, there's footmarks there. They aren't huge at the moment, but our quicks will open those up a little more with the way they hit the crease and where they land on the wicket. For Mitchell Swepson, there's enough there from the end he'll bowl at, there's some cracks opening. It's going to be difficult."
Carey's introduction to Karachi, immortalised on camera, was a tumble into a swimming pool. But over the last two days, he and his side have taken to the city's cricket stadium like ducks to water.