Ricky Kelehar: Cech has been outstanding today - four fantastic saves. Dread to think what could have been without him. 

James Simpson: Did Cech really leave Chelsea for this rubbish? Best player on the pitch for Arsenal.

Theo Walcott gets 10 minutes, in place of Olivier Giroud. 

Image source, Reuters

Danny Mills
Ex-England defender on BBC Radio 5 live

If Arsenal were to nick one back it would make for a fantastic final 10 minutes...  

2-0 up at home to your biggest rivals and you can bring on (probably) your best midfielder. Life is good for Spurs at the minute.

On comes Mousa Dembele for Son.

Brilliant from Victor Wanyama, who shows he has the painting brush to go with the wrecking ball. He cuts out an errant pass, motors into space and then threads a pass through the eye of the needle with the outside of his boot. A gem.

Harry Kane should score - but he is denied by Petr Cech, who then pulls out an even better save to deny Toby Alderweireld.

Cech has had a cracking game. Needed to. 

Simon Crisp: Tottenham are just better than Arsenal. Would be nice if fans could just admit it rather than trying to find someone to blame.

Hector Bellerin is on for Arsenal as they go to a back four. It's a front four they need. 

Nacho Monreal is now booked as referee Michael Oliver seems to have remembered that it's derby day and he'd better get involved.

Olivier Giroud is now booked for an  identical challenge to Harry Kane's a moment ago. You get the feeling Arsenal would take full-time now. They are not convincing that they have any real belief left in the tank, as Danny Welbeck skims a tame effort on goal and then clashes with Toby Alderweireld. 

Mark Mann: More than 20 years to think of something and it's St Gunnneringhams Day. Really?

Harry Kane now booked for a glancing blow on Gabriel. 

Danny Mills
Ex-England defender on BBC Radio 5 live

The second goal has stunned Arsenal. Probably being 2-0 down is a bit unfair. They've worked hard and played a high tempo. Spurs have just had that little bit more quality.

Image source, Getty Images

Jake in Maidstone: Cash in on Ozil in the summer. If he can't be bothered to show up for half a season then allow Ramsey a chance in CAM where he played so well for Wales in the euros. Shambolic. 

Gabriel in the book for a lunge on Dele Alli - he does like to dive in - before Alexis Sanchez goes down hurt after a tackle in midfield. No fight in this Arsenal side. Not today, at least.

Image source, Reuters

Danny Mills
Ex-England defender on BBC Radio 5 live

Alexis Sanchez's arms are raised, but they are sort of covering his face. He's got to protect himself at all times. He's got a sore lip.

Spurs are all over Arsenal now. They want a penalty as Son flicks the ball into Alexis Sanchez, who blocks it with both hands. Corner given, and Harry Kane heads it into the side-netting.

Arsenal cannot live with Tottenham at the moment. 

Ian Marks: I am really, really going to miss White Hart Lane.

Gulled Warsame: How good is Mauricio Poch? No one is mentioning him but what a man! Pep and Mourinho are mediocre.

Alex Storey: Earlier in the season, BBC published a tweet from a Spurs fan calling for Poch's head after a sticky spell. Worst. Call. Ever. 

Great strike!

A corner goes right through the area, Victor Wanyama retrieves it and sets it back for Jan Vertonghen, who sweeps a shot toward the top corner and only a fine save from Petr Cech keeps it out!

Image source, Reuters

That's three penalties today which have divided the footballing world then. Spurs go close again with Toby Alderweireld's header well blocked by Kieran Gibbs. 

Danny Mills
Ex-England defender on BBC Radio 5 live

Some will say yes it's a penalty, some will say no. It's not clear-cut either way, but I felt Harry Kane's reaction was late and he threw himself to the ground.

Sean McGreal: Three cases today of the attacker looking for the contact and getting the pen. Time for a look at laws of the game here? 

Dave Wood: Today's games have certainly added fuel to the argument in favour of video replays. 

Ash Williams: Kane's penalty decision much clearer than Rashford's dive earlier.