Angel Di Maria's second-half goal was enough for Real Madrid to start its Champions League campaign with a 1-0 win over Dinamo Zagreb in Group D on Wednesday.

Di Maria finally broke the deadlock in the 53rd minute when Cristiano Ronaldo, Karim Benzema and Marcelo combined to set up the Argentine winger to curl in from the right.

Marcelo was sent off in the 73rd when he earned a second yellow card for diving under Jerko Leko's challenge and Madrid's players were unhappy with several refereeing decisions.

''We are very happy with the three points we took, but I'm not so satisfied with the refereeing. I hope we never have this referee again,'' said Ronaldo, who received stitches on his right ankle from one particularly robust tackle.

Madrid began its quest for a 10th European Cup playing in red for the first time in 38 years and only the second time ever.

Zagreb created plenty of opportunities but only once troubled Iker Casillas in goal, while the 23-year old Ivan Kelava pulled off a string of saves at the other end.

''I don't like losing but I'm happy with the team,'' Dinamo coach Krunoslav Jurcic said. ''We're playing in the Champions League and this is a very nice experience for us.''

Dinamo was playing in Europe's elite competition for the first time since 1999 and was roared on by a vociferous 28,000 crowd at the intimidating Maksimir Stadium.

''There are always games with such atmosphere and such pressure, we have to be able to handle these environments,'' said Madrid's assistant coach Aitor Karanka.

Karanka took charge while coach Jose Mourinho served the second of his three-match ban for his outburst during the semifinal series against Barcelona last season.

''We know there will be tougher opponents lying in wait for us, but it's not easy to win against anyone,'' Karanka said.

Madrid certainly did not have an easy ride. The home side forced two corners in the first minute and maintained the pressure to prevent the Spanish giant from imposing its game.

Ivan Tomecak and Sammir had alarm bells ringing in the visiting defense, before Fabio Coentrao and Benzema both went close in the 11th, when Madrid began to enoy some possession.

The excellent Kelava was called into action shortly afterward, snatching the ball from the feet of Di Maria, before pulling off a double save from Di Maria and then Mesut Oezil from the rebound in the 29th.

Casillas had to stay tall to deny Ante Rukavina in a one-on-one in the 33rd when Leko sprang the offside trap with a perfect through ball.

Uncharacteristic mistakes from Madrid - mislaid passes from the unusually subdued Oezil and Xabi Alonso - encouraged the home fans, but the Dinamo players were unable to take advantage.

Dinamo's Brazilian striker Sammir missed two further good chances in the second half when he failed to shoot both times.

Di Maria made the home team pay, when he unleashed a curling shot across goal to give Kelava no chance.

The goalkeeper's flying save denied Ronaldo a minute later, and he pulled off another to block Coentrao from the ensuing corner.

Kelava pulled off further good saves to prevent Benzema, Oezil and Ronaldo from making the game safe.

Dinamo pushed hard for an equalizer, but couldn't salvage a point despite Marcelo's dismissal with almost 20 minutes remaining.

The result put Madrid top of Group D, with Ajax and Lyon drawing 0-0 in the section's other match.