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

But there have been goals in Ukraine - Shakhtar Donetsk have raced into a 2-0 lead over Belgian club Anderlecht. Game over already?

Johnny: Dortmund playing rondo with the Spurs defense. Easy.

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

"Pierre-Emerick Aubameyang had one chalked off for offside earlier but there was no doubt about this one. He rose majestically, nodding down right into the far corner. Hugo Lloris had no chance."

Image source, Reuters

Some nice football from Spurs as they come forward before Kieran Trippier's cross is deflected behind for a corner. Roman Weidenfeller is quick off his line to claw the ball out of the air from the set piece.

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

"Spurs are having to work really hard chasing the ball but they're still managing to keep a good shape, they're keeping their discipline. And that's forcing Dortmund into playing a few longer balls." 

Hugo Lloris is quick off his line to clear a ball into his area from Mats Hummels before Marco Reus can reach it. Tottenham have done well to get to 25 minutes without conceding and, for the first time in this game, the decibel level has dropped. Frustrate the home fans and Tottenham might have a chance.

Lee: I think a lot of people are being very disrespectful of this Spurs starting line-up. They are more than capable of getting a draw here which would make us favourites going back to White Hart Lane for the second leg.   

Dortmund look to have targeted Ben Davies down Tottenham's left. Both Henrik Mkhitaryan and Erik Durm are enjoying some space down there, with Davies getting little support from his team-mates.

The two Dortmund players combine to win a corner off Davies, but it comes to nothing.

Image source, AFP/GETTY

A welcome release of pressure on the Tottenham defence as Spurs go on the attack for the first time in about 15 minutes. A flutter of excitement as Son Heung-min gets between two defenders but his first touch from Christian Eriksen's ball is a poor one and the opportunity is gone.

Image source, Reuters

Leigh: Can't believe how lightning quick this game has been so far. Rotation definitely necessary...

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

"The flag went up very quickly but it really was a close call as to whether Pierre-Emerick Aubameyang was offside. What a fierce shot by Henrikh Mkhitaryan - Hugo Lloris did well to react but palmed it straight out to Aubameyang."

Image source, Reuters

I really, really hope Tottenham's defenders had their porridge this morning. They probably should have had a double helping too. It is going to be a long night for them and they'll need all the energy they can muster. Tottenham can't get the ball off Dortmund at the moment.

Image source, Reuters

Ryan Lewis: Bit of a 50-50 squad tonight. I would rather go for the league than Europa. I would rest Kane and Alli in both games.

Sam Freeman: Disappointed with the Spurs starting XI. Dortmund could be out of sight before the home leg. Prove me wrong lads.

Tottenham escape as Henrikh Mkhitaryan lets fly with a piledriver of a shot from outside of the area that Hugo Lloris can only palm back into the middle of the box. Pierre-Emerick Aubameyang pounces on it, sidefooting the ball into the net but as he races away to celebrate he spots the offside flag being raised.

There was a huge roar as Aubameyang slotted home but the decision to rule out the goal was correct.

Image source, Reuters

Another chance for Dortmund.

The ever dangerous Pierre-Emerick Aubameyang starts and finishes it, flicking a pass with the outside of his boot to Marcel Schmelzer, whose cross is volleyed onto the roof of the net by Aubameyang. 

Good work by Tom Carroll, who did just enough to put Aubameyang off his stride.

Image source, Getty Images

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

"Spurs had started very confidently - pressing Dortmund high up the pitch and not allowing them to control the tempo, but the way Thomas Tuchel's side go through the gears really is impressive. Dortmund can be really incisive and the pace they possess is frightening." 

Image source, Reuters

Borussia Dortmund are so quick to get players forward and Ryan Mason and Tom Carroll in the Spurs midfield are finding themselves swiftly surrounded by yellow shirts whenever the hosts have the ball. 

As good as Tottenham's start has been, there is a good reason why Dortmund are unbeaten so far in 2016 - and they have two good chances in quick succession. 

First, Gonzalo Castro fires over from a knockdown, before Pierre-Emerick Aubameyang splits the defence with a pass for Erik Durm, but he pokes the ball just wide of the far post.

Image source, Getty Images