Bayern Munich manager Jupp Heynckes was left to rue his side’s defensive errors after they lost 2-1 to Real Madrid in their Champions League semi-final first leg clash at the Allianz Arena.

Madrid, eyeing a third straight title, needed a 44th-minute equaliser by Marcelo against the run of play to cancel out Joshua Kimmich's opener after Bayern, chasing three trophies this season, had missed a hatful of early chances.

A quick break allowed Real substitute Marco Asensio to beat Sven Ulreich with a fine effort and grab the winner in the 57th minute.

Both of the Madrid goals came about through misplaced Bayern passes however and Heynckes was unhappy with how wasteful his side were in front of goal and their defensive lapses.

"It was a curious game," Heynckes said. "We gifted Madrid two goals through our mistakes.

"We had really good chances and we did not use them. One should not be surprised that we lost. When you have that many chances and you don't score then you cannot win."

The result was identical to last year's quarter-final first leg between the teams before Real won the return game as well on the way to the first successful Champions League title defence.

However, while the Spanish giants have the lead and two crucial away goals, Madrid manager Real coach Zinedine Zidane is taking nothing for granted with the second leg at the Bernabeu yet to come.

"We are satisfied with the result but this does not count for much," Zidane told reporters after the game.

"You can never feel absolutely safe in football.

"We won tonight and I think we played well, we got a good result after a hard game."