Cristiano Ronaldo was sent off for Juventus in his UEFA Champions League debut on Wednesday, but his side were nevertheless able to record a 2-0 over Valencia.
Elsewhere, Manchester United ran out 3-0 winners against Young Boys, the same scoreline Real Madrid enjoyed at home to Roma, while Lyon stunned Manchester City 2-1 at the Etihad Stadium.
Meanwhile, Bayern Munich eased to a 2-0 win over Benfica.
Here are all the results from Wednesday's action:
And the standings after the first matchday:
Group E (Matches, Wins, Goal Difference, Points)
1. Ajax: 1, 1, +3, 3
2. Bayern Munich: 1, 1, +2, 3
3. AEK Athens: 1, 0, -3, 0
4. Benfica: 1, 0, -2, 0
1. Lyon: 1, 1, +1, 3
2. Shakhtar Donetsk: 1, 0, 0, 1
3. Hoffenheim: 1, 0, 0, 1
4. Manchester City: 1, 0, -1, 0
1. Real Madrid: 1, 1, +3, 3
2. Viktoria Plzen: 1, 0, 0, 1
3. CSKA Moscow: 1, 0, 0, 1
4. Roma: 1, 0, -3, 0
1. Juventus: 1, 1, +2, 3
2. Manchester United: 1, 0, +3, 3
3. Young Boys: 1, 0, -3, 1
4. Valencia: 1, 0, -2, 0
Full standings available, per the tournament's official website.
Ronaldo was less than half an hour into his first Champions League match for the Bianconeri when he earned a red card after coming together with Jeison Murillo:
Sports writer Paolo Bandini believes he was perhaps unfortunate to receive his marching orders for the incident:
Paolo Bandini @Paolo_Bandini
So yup, he does pull Murillo's hair for a fraction of a second. Not a clever thing to do and, yeah, you can get sent off for that. Having seen it properly I'm not convinced it'll get overturned on appeal, even if a lot of refs would have left it at a yellow or a talking to.
A two-match ban would see Ronaldo miss Juve's clash with his former side United at Old Trafford in October.
Fortunately for the Bianconeri, Miralem Pjanic was on hand to dispatch two penalties to ensure they came away with three points despite paying for an hour with 10 men.
Meanwhile, City got their Champions League campaign off to an inauspicious start.
The Sky Blues failed to heed a warning when Maxwel Cornet had a goal disallowed for offside, and the forward quickly struck again to give Lyon the lead before Nabil Fekir made it 2-0 before half-time.
Bernardo Silva pulled one back for City in the second half, but they were unable to complete a comeback.
Bitter rivals United had a much more positive night, thanks largely to Paul Pogba, per football analyst Dave O'Brien:
The Frenchman crashed home a fine left-footed finish to open proceedings before tucking away a penalty, and he set up Anthony Martial for United's third.
Although it finished with the same scoreline, Real's win over Roma was even more dominant. Isco, Gareth Bale and Mariano Diaz all got on the scoresheet, but on another day they could have doubled their tally, such were the opportunities they created against the Italian side.
Robert Lewandowski handed Bayern the perfect start at Benfica when he found the net after 10 minutes.
On his return to his former club, Renato Sanches sealed the win with his second-half strike.