Slavia Praha 0-2 Borussia Dortmund
Borussia Dortmund got their campaign up and running in Group F after defeating Slavia Praha 2-0 at the Sinobo Stadium.
After starting the tournament with a goalles draw at home to FC Barcelona, Achraf Hakimi got the Bundesliga side off to a good start after opening the scoring in the 35th minute.
The Morocco international was not done there as he completed his brace on 89 minutes with another composed finish to wrap up the victory for Dortmund.
Dortmund will host Inter Milan on match-day three while the winless Slavia Praha take on FC Barcelona.
Genk 0-0 Napoli
Napoli endured a frustrating evening after being held to a goalless draw by KRC Genk in Group E.
Carlo Ancelotti's men certainly fancied themselves as favourite after the match-day one win over Liverpool, but they were let down by poor finishing on the night as Genk claimed their first point of the campaign.
Genk will take on the defending Champions Liverpool in their next group encounter, while Napoli travel to Red Bull Salzburg.