Luis Diaz is on a one-man mission to get Liverpool back into this game. His bullet header from Trent Alexander-Arnold's cross is tipped over by Alex Meret.

Spurs go direct with a ball being hooked into the area but Richarlison heads over.

Jonathan Woodgate
Former England defender on BBC Radio 5 Live

I’m disappointed Kvaratskhelia’s gone off, because I was enjoying his performance. His pace, his power, he wants to beat his man. He’s another one who you can see going to the Premier League in the next few years.

Giovanni Simeone leaves the ball for Hirving Lozano, who hammers over. The offside flag goes up anyway. A rare example of Liverpool's high line working tonight.

Here's the change for Tottenham on the hour mark.

Emerson Royal makes way for Dejan Kulusevski.

A change in system, then?

Napoli left-back Kim Min-jae, another Champions League debutant, does well to stop Trent Alexander-Arnold's long ball finding Mohamed Salah.

Dejan Kulusevski getting readied by Antonio Conte.

The Italian needs a gamechanger, it's drifting and running away from them at the moment.

Oh! Great save!

Stephen Eustaquio picks up the ball for Porto and drives towards goal. He takes on the shot from about 25 yards and it forces Atletico Madrid keeper Jan Oblak to fingertip round the post.

The closest we've come to a goal in this game.

Napoli bring on Hirving Lozano and Alessio Zerbin for Khvicha Kvaratskhelia and Matteo Politano.

Liverpool will be glad to see Kvaratskhelia come off.

But having seen the opposition go down to 10 men, Spurs are still very slow and ponderous and yet to work goalkeeper Pau Lopez.

Surely they have to step it up soon?

Liverpool have been a bit better since the restart but that isn't saying much. Andy Robertson's cross is headed away. Khvicha Kvaratskhelia goes it alone with a counter but his shot is blocked.

Andre-Frank Zambo Anguissa almost pokes the ball through to Giovanni Simeone for a one-on-one but doesn't get enough power on the pass. Escape for Liverpool.

Jonathan Woodgate
Former England defender on BBC Radio 5 Live

He’s been absolutely magnificent, Kvaratskhelia. His name isn’t the easiest to pronounce, but he’s been very good.

Spurs, with their man advantage, are keeping hold of the ball and pulling Marseille right and left.

They need to be patient for their openings, but when one comes along they'll need to gobble it up.

Son Heung-min collects the ball outside the box but the contact is horrible and it's screwed wide.

Image source, Getty Images

A sign that Liverpool's half-time sub has worked.

Khvicha Kvaratskhelia tricks his way past Trent Alexander-Arnold, as he did in the first half, but Joel Matip steps in to stop him. In the first half he'd have skipped past Joe Gomez too.

Atletico Madrid thought they'd got the opener but the goal has been ruled out for offside.

A cross from the right was headed back to the edge of the area for captain Koke, who beautifully caressed into the bottom corner but the offside flag goes up and VAR quickly confirms it.

It remains 0-0 against Porto.