It had been possible to feel the demons circling from Tottenham’s previous cup tie; their only one before this under Ange Postecoglou. Back in August, the manager had made sweeping changes at Fulham in the Carabao Cup and watched his team exit on penalties. Postecoglou knew that he could ill afford a repeat. The second half of the season might have come to look rather stripped back, especially with no European football. He went with his strongest available lineup and, after an encouraging opening, it all went a little flat. His players looked heavy-legged. Burnley, whose clear priority is Premier League survival, have looked better in recent weeks. Were they about to enjoy an FA Cup tonic? Pedro Porro would dismantle the notion, making the decisive intervention as the clock ticked down towards a winter break-disrupting replay. It was a goal that advertised his tenacious pressing and the purity of his shooting technique. It was some way for him to open his account for the season. Spurs had offered little in the second half. Frankly, they had not done much in an attacking sense after the opening 15 minutes. And when Richarlison allowed a half-chance to slip away, Postecoglou put his hands up to his face. It was tough to watch. And not only that moment. Enter Porro. Burnley tried to play out immediately through their cup goalkeeper Arijanet Muric, up to Zeki Amdouni, but Porro was there, pushing high to win possession. And when he put his laces through the ball, 25 yards out, to the right of centre, the shot fairly zipped into the far, top corner. Porro knew as soon as he unloaded it. Spurs looked home and hosed. And yet they still found a way to dice with disaster during the seven minutes of added time when, out of nowhere, Burnley found another gear and almost equalised. Twice, Muric brought his 6ft 5in frame forward for corners, the first after the Spurs substitute, Pierre-Emile Højbjerg, had made a vital block to deny Hannes Delcroix. On the second, Muric flicked on with his head and there, unmarked, was Amdouni. The offside flag went up but it was not clear whether the decision was correct. It did not matter because Amdouni headed off target. That hammering you might have heard was the sound of Postecoglou’s heart. The victory was hard fought and not without its cost. Postecoglou reported that Ben Davies had suffered a hamstring injury while Giovani Lo Celso felt some muscle tightness. Still, it was a victory and the manager was not about to argue how it came. Postecoglou had said on Thursday that he had no regrets over his Carabao Cup selection against Fulham. He is not the type of guy to second-guess himself. There was no messing about here and it had to feel good to be able to name Micky van de Ven and Ryan Sessegnon among the substitutes. The latter would come on for his first football in 11 months. He would nearly score for 2-0. Spurs had advertised the breakthrough at the outset, Richarlison twice surging up the channels only to finish tamely. The first one was the better chance, Oliver Skipp playing the final pass and it was disappointing to see Richarlison drag past the far post. There was also the moment when Brennan Johnson cut inside from the left and shaped a curler for the far corner. Muric made a smart save. Yet Postecoglou’s players ran into problems, the tempo ebbing from their play, the ideas, too. They entered some good areas, Johnson especially. But they were wasteful. Burnley grew and it was they who created the clearest opening of the first half. Amdouni played a give-and-go with Anass Zaroury, who was one of five changes that Vincent Kompany made from last Saturday’s league defeat at Aston Villa, and what a return ball it was from him; outside of the boot, lifted over the Spurs backline. Amdouni waited for the bounce, which did not really work for him and then his touch was poor. Checking back, he ended up blazing high. It was a let-off for Spurs; a reminder. Johnson would volley off target from a Porro cross – he did not get a clean look at the ball – and it was plain that Postecoglou needed more in the second half. It was noticeable how Postecoglou sent his players out early for the second period. And that Muric began to delay his goal kicks. The crowd gave vent to their frustration. It all came to feel a bit predictable from a Spurs point of view. They needed faster passes, more incision. Dejan Kulusevski cut inside and curled high; Johnson got a volley all wrong. Burnley were comfortable. Johnson would work Muric with another volley and Spurs found themselves hoping for a break from the VAR, which did not come. None of a clutch of reviews throughout the game were ever likely to. The feeling took hold with increasing force that it might be one of those nights when only one moment was needed. Porro would provide it.