Ronaldo, who also got a hat-trick in Sunday’s 5-1 La Liga over Deportivo La Coruna, scored in the 42nd, 79th and 81st minutes with Karim Benzema getting Madrid’s other goal.
The win was the perfect wrm-up for Madrid ahead of this weekend’s mouthwatering league trip to Barcelona.
Jose Mourinho’s side now boast two wins from two in Group D and have opened up a two-point lead after nearest challengers Borussia Dortmund were unlucky to come away from their trip to Manchester City with only a draw.
Dortmund totally dominated the game and took the lead in the 62nd-minute lead through Marco Reus. By then Dortmund could have been four or five goals up, but thy ran into an inspired Joe Hart, who single-handily kept Man City in the game. And Dortmund paid for not taking advantage of all the chances they created when Neven Subotic was harshly penalised for handball and Mario Balotelli coolly rolled in his shot to salvage a 1-1 draw.
In Group B, Arsenal also boast a 100% record after beating Olympiacos 3-1 at the Emirates. Gervinho’s 42nd-minute opener was cancelled out before the break by Kostas Mitroglou’s glancing header, but Lukas Podolski drilled in a low shot to put the Gunners back in front in the 56th minute before Aaron Ramsey wrapped up the win late on with a neat chip.
Schalke are in second spot on four points after being held 2-2 at home by 10-man Montpellier. Karim Ait-Fana gave the French champions a 13th-minute lead but Schalke drew level through the impressive Julian Draxler soon after before Klaas Jan Huntelaar put the home side ahead in the 53rd minute from the penalty spot.
Montpellier also saw Garry Bocaly sent off in that incident but Schalke could not make the most of their numerical advantage or a host of good opportunities and they paid the price when Souleymane Camara scored a 90th-minute equaliser.
Elsewhere. Porto moved three points clear in Group A after James Rodriguez’s 83rd-minute goal earned them a 1-0 home win over big-spending Paris St Germain.
Dynamo Kiev, who lost 4-1 to PSG in their first outing, joined the French outfit on three points after beating Dinamo Zagreb 2-0, the goals coming in the first half from Oleg Gusev and a Josip Pivaric own goal.