There were home wins for Bayern Munich and Real Madrid
Arsenal look like they have it all to do after falling to a 5-1 defeat to Bayern Munich in Germany.
It didn't start well for Arsene Wenger's men as the home side dominated the early part of the game. Arsenal could barely get hold of the ball before Arjen Robben cut in from the right on his favoured left foot and curled a long range effort past Ospina in the Arsenal goal.
Arsenal were then handed a lifeline when they were awarded a soft penalty for foul on Koscienly. Sanchez stepped up but saw his tame effort saved by Neuer only to eventually power the rebound past the German international at the second time of asking.
It stayed level until the break and the visitors appeared reasonably happy given they were second best for most of the half.
However, they lost defender Koscielny after a minute of the second half with Gabriel taking his place.
Bayern upped the tempo and three goals in a ten minute period may well have killed off the tie. Goals from Lewandowski and two from Thiago gave the German champions a 4-1 lead.
Late on, Muller added to the humiliation with a fifth after the English side's defence was run ragged.
It could have been much more as Bayern peppered the Arsenal goal for the majority of the half and the Londoners have it all to do if they are to progress.
Real Madird survived an early scare to take a commanding lead to Italy in a couple of weeks time.
Insigne had given Napoli a shock lead in the 8th minute before Benzema powered in a header to level the scores.
Kroos gave the World Club champions lead when he curled one in from the edge of the area at the start of the second half.
Casemiro cemented the Spaniards lead with an excellent volley to make it 3-1 and it stayed like that until the end.