Tottenham have it all to do in next week's second leg after they slipped to a 1-0 defeat against Ajax.
Spurs went a goal behind after 15 minutes when Donny van de Beek found himself behind the home defence with just Hugo Lloris to beat.
The midfielder steadied himself before shooting low to Lloris' right to open the scoring for the visitors.
Tottenham lost defender Jan Vertonghen before the break when he suffered a head injury after an aerial clash with team-mate Toby Alderweireld.
Mauricio Pochettino's men improved after the break but they were lucky not to concede a second when David Neres struck the post.
Here's how they rated:
Tottenham 0-1 Ajax: 6 talking points as Dutch giants secure first-leg victory
Tottenham medical staff branded 'disgusting and pathetic' for Jan Vertonghen treatment
Tottenham
Lloris 7
Made a smart save in the first half to keep Spurs in the conest.
Trippier 6
He played van de Beek onside for Ajax’s opening goal. Got better.
Sánchez 6
Struggled badly at times but never gave up and made some good blocks.
Alderweireld 7
Was screaming at his team mates in frustration, defence struggled.
Vertonghen 6
Went off concussed but shocking that he was allowed to play on briefly.
Rose 7
Back to his very best combative form, battled for everything. Excellent.
Jan Vertonghen suffers horror head injury in clash against Ajax
Wanyama 5
Looked slow and unable to keep up with Ajax’s slick movement.
Eriksen 7
Tried to make things happen, nice moments and touches.
Alli 6
Gives his everything but a broken hand in a cast cannot help.
Lucas 6
Quiet first half but got better after Sissoko came on and Spurs improved.
Llorente 6
Effectively the third choice striker and struggled to make an impact.
Substitutes:
Sissoko 7
Made the world of difference for Spurs when he came on.
