Milan Rathnayaka, Asitha Fernando's strikes jolt Pakistan

Realistically, Pakistan couldn't win going into the final day of the first Test in Rawalpindi. But they could lose it. A superb bowling session from Sri Lanka took giant strides towards ensuring that possibility grew ever more realistic across an absorbing morning of play, in in which they took four wickets and began to burrow into Pakistan's lower order. It leaves Pakistan leading by an insecure 139 at lunch, vulnerable to a collapse that would leave Sri Lanka with a narrow but realistic path to victory.

If anyone was groggy after overnight rain and a damp morning, they were jolted awake after the first ball. Azan Awais lazily drove with hard hands and edged Lahiru Kumara to second slip, and found his work done for the day. Five balls later, Mohammad Taha was taking his leave, Sri Lanka showing how disciplined they were prepared to be by tormenting him in the channel outside off stump and drawing the edge.

Out strode Babar Azam and Saud Shakeel. Invaluably for Pakistan they took time out of the game by keeping Sri Lanka at bay for the next hour, taking very different approaches. Babar was expansive, positive even, through his innings. On occasion, he would launch into regal drives through the covers or straight down the ground, or flick and pull into gaps to keep that lead growing. Shakeel preferred steek to flair, especially disciplined in leaving balls outside the line of the stumps, those decisions made more challenging by the relentless accuracy of the quick bowlers.

Pakistan's supporters desperate to see signs of vintage Babar might have found some evidence to cling on to through his knock, though the visitors have every right to dispute that. Asitha Fernando, perhaps the pick of the bowlers, squared him up early in the innings and fractionally beat both outside edge and off stump, and Babar was much less convincing when judging what to leave. Shortly after, Fernando had him prodding at a seaming delivery outside off stump, getting an edge that floated to Kamindu Mendis, who somehow dropped a straightforward catch. The following over, Milan Rathnayaka only just failed to send him back lbw after an umpire's call went the other way.

With conventional tactics not quite working, Sri Lanka turned to street-smarts. They placed a fielder at short square leg and peppered his pads, and Babar waltzed into that trip, wristily flicking the ball precisely where that fielder had been placed. At the other end of a brief delay for bad light, Salman Agha did the same, though it needed Pasindu Sooriyabandara to take a blinder.

Pakistan's lead had barely passed 100 with more than two sessions to go, and Sri Lanka suddenly looked as if they could overwhelm them. The stubborn Shakeel and Ghazi Ghori kept the visitors at bay for what remained of an extended morning session, but Sri Lanka are not done sniffing. It may take a combination of lower-order resistance and Rawalpindi's gloomy skies to stave off a remarkable Sri Lankan win.