The round of 16, first leg bore more resemblance to a playground kickabout than Europe's top club competition as Schalke kept giving the ball away to Real, who simply ran down the other end of the pitch and scored. (Agencies)
Gareth Bale, Karim Benzema and Cristiano Ronaldo scored twice each and Real could quite easily have added to their tally against opponents who started promisingly but completely lost their composure after conceding two goals in a disastrous eight-minute first-half spell.
Incredibly, the home fans kept singing until the end and were rewarded when Dutch striker Klaas-Jan Huntelaar volleyed in from the edge of the area for a stoppage-time consolation.
The result, Schalke's heaviest defeat in European football, was the second embarrassment for the Bundesliga following Bayer Leverkusen's 4-0 humbling at home by Paris St Germain last week.
Real, who also won 6-1 at Galatasaray in the group stage, took their tally in the competition to 26 goals in seven games, 11 of them from Ronaldo.
"We made too many simple mistakes," shattered Schalke coach Jens Keller told ZDF television, his tie undone and his hair flopping to one side.
"We should have equalised straight away to make it 1-1, but it was just mistake after mistake.
"We were brave for the first 12 minutes, then they scored and then they got a second goal after a huge mistake by us. I have a young team who wanted to go forward but we should have been tighter."
"I'm satisfied with everything because that was the perfect game," said Real Madrid coach Carlo Ancelotti.
"My players played with togetherness and they played well. Everything came off for us. The front three all scored twice but they also had the help of their team mates," he said.
The round of 16, first leg bore more resemblance to a playground kickabout than Europe's top club competition as Schalke kept giving the ball away to Real, who simply ran down the other end of the pitch and scored.