Wolfsburg, Germany: Zinedine Zidane's Real Madrid suffered a shock 2-0 Champions League defeat at Wolfsburg in Wednesday's quarter-final, first-leg to leave them on the verge of a European exit.

Just five days after ending Barcelona's 39-game unbeaten run with a 2-1 away win in El Clasico, Real were humbled as Wolfsburg ignored their struggling mid-table form in Germany's top flight.

Real never recovered as first-half goals from Swiss defender Ricardo Rodriguez and Maximilian Arnold put the hosts 2-0 up at the Volkswagen Arena with 25 minutes gone.

"I'm not happy, above all with the first-half. This can happen If you don't play with intensity from the start," said Zidane.

"Despite everything I'm proud of the team, we have to think about resting well and think about the return because we have the chance to change this in the return leg."

Real's six-game winning streak was ended as Wolfsburg picked up their first win in four games since beating Gent in the last 16 of the tournament.

To give the result context, Wolfsburg needed a 93rd minute equaliser to seal a 1-1 draw with relegation-threatened Darmstadt on their last home league appearance.

There was no hint they would bother Real when they crashed 3-0 at Bayer Leverkusen last Friday in Germany's top flight.

But having also beaten Manchester United 3-2 at home in the group stages, Wolfsburg now have the upper hand ahead of Tuesday's return leg at the Bernabeu.

But goal-scorer Arnold insists nothing has been decided yet.

"There is no point getting carried away. We have only finished 55 percent of the job," he said after his first Champions League goal.

It was a poor performance from Real's star forwards as Gareth Bale was kept quiet and Cristiano Ronaldo rarely shook of his markers.

France forward Karim Benzema went off on 41 minutes after a knock.

Zidane had made just one change -- Danilo in for Dani Carvajal at right-back -- from the ten-man side which beat Barcelona.

Wolfsburg coach Dieter Hecking gambled by starting inexperienced Brazilian Bruno Henrique on the right wing.

Centre-back Naldo was also rushed back after dislocating his shoulder in February, but both selections were rewarded.

There was little hint of the drama to come as Real needed just 74 seconds to put the ball in the Wolfsburg net.

Ronaldo made a late run and tucked his shot past Diego Benaglio, but the offside flag went up.

The hosts started to find their feet before taking a shock 18th minute lead.

Italian referee Gianluca Rocchi pointed straight to the spot when Real midfielder Casemiro put in a clumsy foul on Wolfsburg striker Andre Schuerrle.

Real goalkeeper Keylor Navas tried to unsettle the taker, but Rodriguez nailed the spot kick.

It was the first Champions League goal Navas had conceded after 738 minutes.

But he soon leaked a second as Wolfsburg's attack stepped with the Real defence -- especially wingbacks Marcelo and Danilo -- rattled.

Julian Draxler started a move on the right wing, Henrique picked out Arnold's run and the attacking midfielder slotted home on 25 minutes.

Ronaldo tried to drag Real back into the match, but both of his shots flew wide of the Wolfsburg goal in the five minutes after the interval.

In a bid to boost the midfield, Zidane brought on Isco for Luka Modric with an hour gone, but the Spain international had to immediately help snuff out a Schuerrle break.

The Germany winger should have made it three when Draxler started a counter-attack with Henrique, but when the ball found him in space, Schuerre blasted just over with 20 minutes to go.

There was plenty of pushing and shoving immediately after as Arnold clashed with Marcelo, which led to both Arnold and Bale being booked.

Ronaldo then got in behind the defence and fired across the empty Wolfsburg goal, but Benzema's replacement Jese failed to connect as the Germans held on for a famous win.