Zurich - Real Madrid began their bid to reach the Champions League final at their Santiago Bernabeu stadium with a 5-2 Group C win at debutants FC Zurich on Tuesday although it was far more difficult than the scoreline suggests.
Real surged into a 3-0 first-half lead after Cristiano Ronaldo made it three goals in as many games with his first Champions League goal for Real before Raul and Gonzalo Higuain both netted.
However, nine-time European champions Real had to withstand a sterling second-half comeback from Zurich who scored twice in two minutes to give Real a jittery final 20 minutes before Ronaldo and Guti scored late on.
It was not the convincing display Real coach Manuel Pellegrini wanted from his Galacticos' and Real will have to lift their game if they want to improve on a miserable run of failing to get past the last 16 stage for the past five seasons.
Portuguese centre-back Pepe is still serving a long-term domestic ban for violent conduct but is available in Europe and made his first appearance of the season in defence.
Pellegrini has been rotating his ample squad early in the season so both Higuain and Dutch defender Roysten Drenthe started after sitting out the 3-0 win over Espanyol on Saturday.
Ronaldo, Kaka and Xabi Alonso - who all won this competition with their previous clubs - made their Champions League debuts for Real to leave Zurich, making their debut in the group phase, a bit overawed.
However, the Swiss team were pumped up for the challenge and not afraid to put their foot in with Ronaldo coming in for some tough treatment.
The Portuguese star, a losing finalist with Manchester United last season, showed great early skill to beat two players who chopped him down to leave him squirming in pain on the ground.
Real threatened twice through Higuain and Kaka before the breakthrough came from a set-piece on 28 minutes.
Ronaldo stepped up to smash a thunderous free-kick into the roof of the net for his first Champions League goal for the club.
Raul made it 2-0 on 33 minutes sliding home after Higuain put the ball on a plate.
Higuain, controversially ignored by embattled Argentina coach Diego Maradona, added a third close to half-time using his impressive pace to accelerate away before slotting home.
With a three-goal cushion, Real were cruising and went into the second half hungry for more but got a shock.
The outrushing Casillas conceded a 63rd minute penalty for a rash challenge and Xavier Margairaz converted for what many thought would be a consolation goal.
However, two minutes later Silvan Aegerter rose high to head home a corner and make it 3-2 with neutrals wondering whether Real had changed into their white kit at half-time.
Ronaldo scored his second late on with another free-kick although it was a gift which should have been saved by the Zurich goalkeeper. Guti bagged a fifth in stoppage time to make the game look far more comfortable than it was.
Real's next Group C match is at home to Marseille - who lost 2-1 to ACV Milan - on September 30.