Bayern Munich's 4-0 win over Atletico Madrid left Diego Simeone with a "bad taste" but he defended his players after the loss.
Manchester City recovered from an early setback to beat Porto 3-1 in their opening Champions League Group C fixture.
Romelu Lukaku was Inter's hero as his 90th-minute goal salvaged a 2-2 draw with Borussia Monchengladbach in a frantic ending at San Siro.
Shakhtar Donetsk claimed a famous win at Real Madrid despite missing a host of first-team players for their Champions League opener.
Paris Saint-Germain head coach Thomas Tuchel reflected on his team's loss to Manchester United behind closed doors.
Souleymane Camara scored five minutes from time as Montpellier secured a thoroughly deserved win against a woeful Paris Saint-Germain.