Should Tottenham have a penalty? Son Heung-min goes down inside the area under a challenge from Sven Bender. Nothing given, but Tottenham's players didn't make a big song and dance about it.

Just like that, though, Dortmund turn up the wick. 

It is another swift attack as Henrikh Mkhitaryan wipes out the Tottenham defence with a ball into the box for Pierre-Emerick Aubameyang, whose cross towards the far post is met by Gonzalo Castro, but his low shot from a very, very tight angle strikes the base of the upright.

Tottenham survive.

Image source, Getty Images

Slow start to the second half as both sides trade possession in midfield.

Here's a reminder of the teams.

Dortmund XI: Weidenfeller, Durm, Piszczek, Bender, Hummels, Schmelzer, Weigl, Castro, Mkhitaryan, Reus, Aubameyang.     

Tottenham XI: Lloris, Trippier, Alderweireld, Wimmer, Davies; Carroll, Mason, Onomah, Chadli, Eriksen, Son.

A tactical tweak by Mauricio Pochettino as Son Heung-min moves into the lone striker role, with Nacer Chadli swapping places, moving wide left. Should it have been that way from the start? Chadli was largely anonymous in the first half.

Image source, EPA

No changes for either side as Borussia Dortmund get the second half up and running.

Liverpool and Manchester United meet in the Europa League tonight - a clash that Jurgen Klopp describes as the "mother of all games".

You can get the team news and follow live text commentary on that game here.

Image source, Reuters

Mike Dean from High Wycombe: I'm still smiling at the comment that if Spurs had a centre-forward called Head then their front line tonight would be Onomah Head Son!..  

Apart from a shot straight after kick-off by Christian Eriksen, Tottenham have not troubled Roman Weidenfeller in the Dortmund goal.

How long before Mauricio Pochettino is tempted to turn to Mousa Dembele and Harry Kane?

Goalless at the break between Basel and defending champions Sevilla, and goalless in Istanbul too, where Robin van Persie's Fenerbahce are hosting Sporting Braga of Portugal. 

There's better news in Ukraine though - where Shakhtar Donetsk raced into a 2-0 lead over Belgian club Anderlecht after about 25 minutes.

Brent, London: What would a big loss here do to Spurs confidence at the business end of the season?

John Pierce: Despite all Dortmund's great play, still fancy Spurs to grab an away goal...

Clive Allen
Former Tottenham & England forward in Dortmund for 5 live Sport

"Spurs will be relatively happy. They knew it would be difficult and to be only one goal down at the break, I think they have done OK. It's tireless work chasing the ball, but they need to keep calm and keep their shape in the second half, because if they don't this Dortmund side will open them up at any time." 

Image source, Reuters

The whistle goes for half-time. Tottenham would arguably take that scoreline at the break. It has been all Dortmund.

A bit of a worry here for Tottenham as Kieran Trippier takes a knock after a challenge and takes a while to get to his feet. A couple of minutes to get a breather and he is OK to continue, but Spurs can't afford to lose him, he's been their best player today.

Two minutes of time added on.

Image source, AP

Clive Allen
Former Tottenham & England forward in Dortmund for 5 live Sport

"Dortmund are oozing confidence. Tottenham just have to weather the last few minutes of this first half now. Thomas Tuchel's side are so incisive, it really is impressive, and they are all so comfortable on the ball."

Ryan Mason and Tom Carroll are left standing as Dortmund's attack slices through Tottenham like a hot knife through butter. Too easy as Henrikh Mkhitarayn is allowed space 30 yards from goal but his long-range strike is deflected behind. 

Moments later, Mason has to cut out a dangerous Dortmund cross inside the area. The hosts want a second before the break.

Image source, AFP/GETTY

Borussia Dortmund are toying with Tottenham. No rush to clear from just outside their own area as they pass the ball in triangles around the Spurs forwards before nonchalantly getting it up the pitch.

A 1-0 defeat won't be that bad for Tottenham here. Trouble is, there is a long way to go in this game...

Daniel Woods: Maurico, my friend, you have brought a knife to a gun fight with that central midfield selection.

Chipperhull: Dortmund are five points off the lead in their league with nine left - same as Spurs. Yet they pick a full team...

Marcel Schmelzer makes his way off the pitch to receive treatment and Marco Reus steps up to take the free-kick, bending it over the wall and towards the near post but the ball goes just wide.

Fortunate for Tottenham, with Hugo Lloris rooted to the spot.

Image source, Reuters

Ouch!

Marcel Schmelzer takes a boot to the face as he challenges Tom Carroll for a high ball just outside the box. No malice from Carroll, who had his eyes on the ball but a definite booking.

A dangerous position for a free-kick now for Dortmund.

Image source, Getty Images