How deceptive appearances can be. On the face of things this was hardly an assignment Mauricio Pochettino would have asked for with a potentially season-defining match in Barcelona three days away, and to the naked eye his decision to name Harry Kane and Christian Eriksen on the bench seemed to play fast and loose with the evening’s outcome. Yet reality told a different tale: one of a surprisingly comfortable win that at once minimised Tottenham’s stress levels before visiting the Camp Nou and left them aglow with what feels like a renewed set of possibilities on the domestic front.

That they departed so buoyantly owed plenty to Son Heung-min, whose slow start to the season has seemed a distant memory over the past three weeks. A largely dreary first half was drawing to a close when, cutting inside on to his left foot, he cracked a marvellously clean 20-yard shot across Kasper Schmeichel and ended a Leicester resistance that had just begun to appear precarious. He crossed for Dele Alli to score Spurs’ second after half-time and ensure that, with 36 points from 16 games, they have made their best-ever start to a Premier League campaign.

“Now I will allow us to start thinking about Barcelona,” Pochettino said, although Tuesday’s fixture had manifestly crossed his mind well in advance. As Leicester asked questions of Tottenham’s defence in the first 20 minutes, while a mobile but outwardly brittle front three of Son, Alli and Lucas Moura struggled to impose themselves further forward, an inquest into his resource management did not seem unrealistic. But they settled thereafter, keeping possession well enough to deprive the home side of counterattacking oxygen and gradually making inroads in attack. The end product left Pochettino, whose side have responded admirably to their defeat at Arsenal and its surrounding storm, visibly enthused and sufficiently confident to talk up their chances of staying in the title race.

“The reality is that we are there fighting,” he said, having seen Manchester City’s defeat at Stamford Bridge offer a shaft of light to those chasing the top two. “We are in a very good position with Liverpool, City, Chelsea and Arsenal. That is the reality.” They have not drawn any of their last 20 league games; the defeats, when they come, tend to bring doubts about their ability to match those around them but Spurs showed again here that the winning habit is hard to kick.

They limited Leicester’s chances to an early flurry and then, when the game had long since been wrapped up, a succession of crosses flashed across goal. Jamie Vardy was missing for the second week in a row, a groin injury continuing to lay him low, and Kelechi Iheanacho was a nervy stand-in. He shot wildly over when sent away by an early ball over the top although Jan Vertonghen then denied him a tap-in after the overlapping Ben Chilwell had crossed. There were cheers from some sections of the crowd when he was replaced by Rachid Ghezzal early in the second half and Leicester, who have as good a chance as anyone of landing the “best-of-the-rest” spot below the top six, look in need of more potent attacking options in January.

As it happened Ghezzal’s chances of effecting an improvement were nixed almost instantly. Two minutes after he came on, Tottenham’s forwards contrived a tour de force, Moura finding Son on the left and Alli, with characteristically adept timing, running in from the opposite side to head the South Korean’s cross in at the far post. He was arguably a shade offside, but not obviously enough to impact upon the post-match narrative.

The conversation flowed more readily around the head of steam being built up by Son. “I think the first few months of the competition were a bit disappointing because he travelled a lot [with his national team],” Pochettino said. “But he was so focused and tried to improve. Now we are so happy with his performance. That is the player we want, we expect, that energy.”

Now they travel to Catalonia with that vigour spread across the entire team. Kane, whose vigorous applause of Son’s goal from the bench was perhaps laced with relief that he would not be wheeled out for a salvage operation here, received a light runout for the last 20 minutes and Eriksen was afforded only slightly more. The cotton-wool exercise paid off and the only possible dampener for Spurs was an injury to Serge Aurier, who hobbled off to be replaced by Kyle Walker-Peters. It was hardly the biggest of troubles and the benefit of such a stately evening’s work may become apparent soon enough.