For half an hour of the second half at San Siro this looked like the night Internazionale's perfect start would be torn to pieces. Napoli had them two goals down and reeling, the crowd falling quiet, the champions of the table suddenly wearing the faces of a team unsure of itself. And then, in the space of forty frantic minutes, everything turned.

Lautaro Martínez had the last word, as the great strikers so often do, stabbing home from very close range in the first minute of stoppage time to complete a 3-2 win that felt less like a result than a statement of character. Inter had trailed, chased, drawn level and then plundered the winner when the game seemed destined for a share of the spoils. San Siro, so subdued at the hour mark, erupted into something close to disbelief.

It was a match that swung on nerve and belief. Napoli, freshly promoted into the conversation by their early lead, wilted under a relentless finish. Inter, top of Serie A and unbeaten, showed exactly why they sit where they do — not because they were flawless, but because they refused to lose.

Napoli's early ambush

The visitors could scarcely have imagined a better opening to the second period. Five minutes after the restart, Matteo Politano collected possession in the centre of the box and steered a right-footed shot low into the bottom-left corner, silencing the home support and handing Napoli a lead their first-half endeavour had barely threatened to earn.

Three minutes later they doubled it, and this time the finish carried real venom. Rasmus Højlund, fed by Giovanni Di Lorenzo, took aim from outside the box and lashed a left-footed strike into the same bottom-left corner, beyond reach. Two goals in three minutes, both drilled into that identical pocket of the net, and Inter's unbeaten record suddenly looked desperately fragile.

For a Napoli side that had arrived 13th and scratching for form, it was the kind of blistering spell that can define a season. They had scored twice at the home of the league leaders and, briefly, looked every inch the side capable of holding on. But two goals, as they would learn, is a dangerous cushion to sit upon at San Siro.

The response begins

Inter's answer was immediate and instinctive. Barely had Napoli finished celebrating their second when Lautaro Martínez pounced, converting from very close range into the high centre of the goal after Federico Dimarco had supplied the invitation. The margin was halved within three minutes of it being doubled, and the entire complexion of the contest shifted with it.

That goal changed everything. It gave the home crowd a reason to roar again and it planted a seed of doubt in Napoli minds that only grew as the clock wore on. Inter pressed, probed and pushed the visitors deeper and deeper, sensing that the momentum had swung irreversibly into their hands.

Napoli, for their part, retreated into a shell that never looked entirely secure. The lead they had built in a dazzling burst was now being defended with gritted teeth rather than dictated with confidence, and the longer Inter hunted, the more inevitable the equaliser began to feel.

Two blows at the last

It arrived with eight minutes of normal time remaining. Carlos Augusto swung a cross into the centre of the box and Marcus Thuram rose to meet it, planting a header into the bottom-left corner to haul Inter level at 2-2. The stadium shook. What had begun as a rescue mission now carried the scent of something greater.

Napoli might have settled for the point, might even have felt they had escaped with one. But Inter would not be denied. Deep into stoppage time, from a corner, Manuel Akanji nodded the ball into the danger area and there was Lautaro Martínez again, poking home with his left foot from very close range to win it. His second of the night, and the sweetest of the lot.

There was barely time to restart. A team that had been two goals down against the run of play had scored three without reply, the last of them at the death, and San Siro dissolved into scenes of pure release. Lautaro, the captain and the constant, wheeled away as the noise crashed down around him.

Table and trajectory

The victory keeps Internazionale top of Serie A with a flawless record: three wins from three, nine points, eight goals scored and only three conceded. More than the numbers, though, it is the manner of it that will resonate. Champions and leaders are forged in nights like these, when the game is slipping away and the will to reclaim it becomes the deciding factor.

For Napoli the reckoning is harder. A third defeat in four games leaves them marooned in 13th on three points, their goals for and against locked level at five apiece. To have led 2-0 at the home of the league leaders and taken nothing away is the kind of wound that lingers, a reminder that promise counts for little without the steel to see it through.

Inter move on knowing they can trail and still triumph, a quality that separates the contenders from the rest. Napoli must regroup quickly, because performances like their first hour deserve points, and points are precisely what this season is already threatening to withhold from them. The margins were fine; the outcome, in the end, was not.