Liverpool’s Virgil van Dijk outlasts Napoli’s Kalidou Koulibaly in the battle of superhuman centre-backs

What this game would come down to is which of these two unbeatable men would be beaten first, which side could find a David for the other’s Goliath

For all the late drama at both ends, Allison’s save and Sadio Mane’s misses, this game, and Liverpool’s Champions League future, was decided by one lethal little shuffle late in the first half. That was what it took to beat Napoli 1-0, and it was a huge achievement in itself, humbling their heroic Kalidou Koulibaly, bringing the superhuman centre-back down to earth.

This evening was a clash of titans between two of the best defenders in the sport. And so the game, and the place in the last-16 of the Champions League, was decided by which of Koulibaly and Virgil Van Dijk proved to be fallible in the end. Ultimately it was Mohamed Salah in the role of Paris, locating and then striking Koulibaly’s Achilles heel. His first half winner keeps Liverpool in the hunt for Madrid next June.

Before then, Koulibaly had looked imperious and impassable at the heart of the Napoli defence. He looked just as good, in fact, as his rival Van Dijk did at the opposite end. Just as powerful, just as mobile, just as able to glide across the ground to shut down seemingly nimbler attackers. Liverpool looked as if they would struggle to find their way through.

Koulibaly kept up with Salah in a foot race down the right. He burst out of his position to block a Gini Wijnaldum shot. He won the physical tussles with Roberto Firmino. He looked like he always does at his best, like a complete modern defender, able to bear the burden of Napoli’s attacking game on his broad shoulders. Like a man who would improve every team on the planet.

That is the point with the best centre-backs in the modern game. We sometimes accuse defenders today with not being able to defend, or not even being interested in it, but in another sense elite defenders now have more individual responsibilities than ever before. Because the more attacking the top sides get, the more men they throw forward, and the higher up the pitch they defend, the harder it gets for the few men who have to stop the opposition.

That is why the top teams value centre-backs so highly, because they cannot play their expansive football without a defender who can pass. And they cannot afford to play that expansive football without a man back on the half-way line capable of defending one against one when it comes to it. This is the context for Manchester City breaking their transfer record to spend £57million on Aymeric Laporte at the start of the year. Because Nicolas Otamendi would have been a fine defender for a normal team but was not quite up to the demands Guardiola team.

Even more to the point, this is why Liverpool spent £75m on Van Dijk one year ago. Because this is a team that does a lot of attacking and they needed one man who was good enough to do almost all their defending for them. That might be simplistic but to watch Liverpool over the last year has been to see the obvious benefit of filling a big square hole with the best square peg that money can buy.

Mohamed Salah takes on Kalidou Koulibaly (Getty Images)

Van Dijk did not have quite as much defending to do as Koulibaly did, but he had enough, and Liverpool would not have been able to play the way they did without him at the back. Especially given that the injury to Joe Gomez means that Liverpool are even more dependent on Van Dijk’s mobility and authority than they were before. Here he had to do almost everything: heading away set pieces, starting moves, covering off counter attacks. Even more impressive that he did this despite picking up an early booking for a tackle on Dries Mertens, meaning he could not afford the slightest miscalculation for the rest of the match.

So in parts this evening felt like a tight duel between two well-matched teams, but where the two most important players on each side where the centre-backs, Van Dijk and Koulibaly, each there radiating a sense of invincibility, of superhuman strength and speed and foresight and grace.

What this game would come down to, then, is which of these two unbeatable men would be beaten first. Which side could find a David for the other’s Goliath. And there was only one man for it.

Mohamed Salah spent the first half hour trying to test out Koulibably, trying to wonder if Achilles might have a vulnerable heel after all. One sharp dart outside Koulibaly’s left side looked like a tester though, as if Salah might now have an idea of how to do it. And sure enough with his next move, after rolling left-back Mario Rui, he found himself one on one with Napoli’s main man. So he decided to stop, squaring Koulibaly up, freezing him on the spot, before bursting away down the outside.

That was all it took. Rolling the ball through the legs of David Ospina, who dived away from the ball, was far easier.

That was the only goal of the game although in truth Liverpool had plenty of chances and Napoli could have nicked it at the end. But it is easy to get wrapped up in the goals that might have happened. One actual goal was enough, and it belonged to Salah, after he had done what no-one else could do and beaten Koulibaly. If he had not done what had originally looked impossible, then who knows how this would have ended up?