Sri Lanka (Tea) 110 and 17 for 1 (Silva 7*, Mendis 4*) require a further 490 runs to beat

South Africa 392 and 224 for 7 dec (Elgar 55, Lakmal 4-69)

Hashim Amla would have liked to have walked out to bat for his 100th Test at the Wanderers next week with his reputation reasserted. Instead he will take guard with continued worries about his form after a duck on the third morning at Cape Town extended his unproductive run.

Amla’s sequence without a half-century now stretches to 10 innings, his latest failure coming with a fifth-ball nought in an otherwise dreary phase of the Test of little consequence in which South Africa, resuming with a lead of 317 and all wickets remaining, engaged in some cricketing arithmetic for more than three hours as they totted enough runs for a fail-safe declaration. And then some.

That declaration finally came at 224 for 7, 75 minutes into the afternoon session. A lead of 506 was impregnable. Well, not quite impregnable. There was always the slight possibility that a Russian cyberattack could send cricket scoring systems across the world haywire and Sri Lanka could emerge, somewhat sheepishly, with a win late on the fourth day.

Reality was less encouraging. In eight overs up to tea, they lost Dimuth Karunaratne, who was set up nicely by Vernon Philander before he drove airily at an inswinger to be bowled between bat and pad.

Presumably Amla might now join those malcontents who thought, with good reason, that South Africa should have enforced the follow-on with a first-innings lead of 282 and sought to wrap the game up in three days. After all, only three sides have ever lost a Test after putting the opposition back in and, having dismissed Sri Lanka in 43 overs, South Africa’s bowlers were hardly in need of recuperation.

At least it would have spared Amla that sinking feeling when he pushed routinely forward to an excellent delivery, seaming away around off stump, from Suranga Lakmal and felt the nick that was heading inexorably to the wicketkeeper. Lakmal has had a good series and he matched the admirable standards that had brought him five wickets in Port Elizabeth.

As ducks go, this was a highly respectable one. But it was still a duck. It will not quieten the discussions about how Amla tends to get caught on the crease, his graceful footwork no longer quite decisive enough. Only big runs will do that, and everybody presumes they will come. The only time he has had a sequence of failures as long as this was a year ago – and then he shot back with a double hundred against England in Cape Town.

Jo’burg might sharpen his senses. A hundred when it really matters with the pressure on might be a more satisfying return to his magnificent best than to have made essentially worthless runs on a hot morning in Cape Town when the situation was dead, tans were topped up and the cricket was merely window dressing.

Sri Lanka might have been facing what appeared to be inevitable defeat, but they had Nuwan Pradeep back after a thigh strain and they showed decent resolve throughout the morning session.

Lakmal brightened their morning with a double-wicket maiden. Five balls before he dismissed Amla, he accounted for Stephen Cook, a regulation slip catch for Karunaratne.

Dean Elgar, in trim after his first-innings hundred, seemed suited to such a morning. A measured tread with little pressure to talk of was right up his alley and another half-century was bagged. But the appearance of Rangana Herath’s left-arm slows drew from Elgar an unexpected friskiness. He advanced down the pitch to a guileful third delivery which beat him in the flight. If he had not been caught at slip, he would have been stumped. A moment of class on a largely inconsequential morning.

The captain, Faf du Plessis, took South Africa past a 400 lead when he gently guided Pradeep to third man, but Sri Lanka had one more moment of pleasure before lunch. Their fourth wicket was that of JP Duminy, who was lbw to Lakmal on the stroke of lunch, a review failing to save him.

Still, South Africa continued, committed to a lead of more than 500. Temba Bavuma ran himself out for nought – a direct hit from mid-off beating his desperate dive for the crease as his bat bounced – and wicketkeeper catches removed du Plessis and de Kock. Lakmal finished with 4 for 69 in 19 overs and his admirable effort deserved a five-for, which probably explained his enthusiasm for unsuccessfully reviewing an imaginary nick to the keeper by Philander moments before South Africa called time.