Real Madrid coach Carlo Ancelotti hailed his team's performance as "perfect" after its 6-1 rout at Schalke 04 in Wednesday's Champions League's last-16, first-leg clash.

Real is now all but guaranteed a quarter-final place, even with the return leg in Madrid to come on March 18, after Karim Benzema and Gareth Bale each tallied twice.

Real's Ballon d'Or winner Cristiano Ronaldo also notched a pair of goals in his return from a three-match Spanish league suspension.

The crushing victory went some way to correcting Real's terrible away record in Germany as it made the Royal Blues of Schalke look anything but regal.

It was only Real's second win in 26 visits to Germany after 18 defeats, including its 4-1 drubbing at Borussia Dortmund in last season's Champions League's semi-final.

"We didn't think about the curse in Germany; just about doing as much as we could to win the game and take control of the tie as quickly as possible," said Ancelotti.

"I am satisfied about everything, because the team played a perfect game."

Madrid is now unbeaten in its past 27 games, dating back to October.

"After the early goal, we started getting a lot of room, that was the reason for our perfect night. It was fantastic ... everything went well for us."

Despite the massive advantage, Ancelotti said the Spanish league leader is taking nothing for granted for the return leg.

"There is a return leg to come and football is strange," he said.

"The advantage is big, but we want to make sure we go through.

"We need to have respect for Schalke and our fans, so we will be putting out our best possible side for the return leg."

Ronaldo has now scored 36 goals in 33 games and his brace saw him take over from Zlatan Ibrahimovic as the competition's top scorer this season with 11 goals.

"The team has played a lot of good games and this is one more," said Ronaldo.

"We played well and didn't allow Schalke to play at their best. We are happy and a step away from the next round.

"The Schalke goalkeeper did very well and made good saves, but I believe in my ability and my teammates helped me a lot.

"I am very happy to score two goals."

Schalke goalkeeper Ralf Faehrmann said his side was totally outclassed as Real fired 21 shots on goal compared to 10 by the host.

"One save against Ronaldo isn't enough," said Faehr-mann. "Real Madrid really showed why they are a class apart.

"When you start conceding goals to that club, it is almost impossible to come back against them."

Netherlands striker Klaas-Jan Huntelaar scored a 91st-minute consolation goal for Schalke.

It did little to prevent the Royal Blues suffering their heaviest defeat in European competition.

"We made too many simple mistakes. After we went down 2-0 it was incredibly hard to come back," said Schalke coach Jens Keller.

"After that, we should have stood deeper, not to concede so many goals, but this is a young team."

Schalke wasted a golden chance to make it 1-1 immediately after Benzema had given Real a 13th-minute lead, but teenage midfielder Max Meyer fired over the bar with the goal at his mercy.

"The first 12 minutes were good, we were brave and aggressive and the team was compact," said Keller.

"We had a huge chance to equalize just after their first goal, but then we just made far too many mistakes.

"All of them were quickly punished and we all saw that Real is a world-class team."

Schalke 04's Klaas-Jan Huntelaar (left) and Real Madrid's Sergio Ramos compete for a header during their Champions League match in Gelsenkirchen, Germany on Wednesday. Real cruised to a 6-1 victory.