Nacho got the hosts off to a ideal start before Ronaldo doubled his La Liga tally for the season with a cool finish and a penalty inside the half mark.
Toni Kroos and Achraf Hakimi rounded off the rout as Real leapfrogged cross city rivals Atletico Madrid into third.
Barca can regain their eight-point advantage over Real when they visit Villarreal on Sunday.
"No player does things that I cannot do myself, but I see things others can't do".
Cristiano Ronaldo's former Madrid teammate, James Rodriguez believes he fully deserves to win a fifth Golden Ball.
Real simply had too much firepower for a Sevilla side who had started Saturday behind their hosts only on goal difference.
Kroos floated a corner over from the right, which defender Simon Kjaer and also striker Luis Muriel tried to clear, but only managed to divert it back into the six-yard box where Nacho lashed it home to give Real the flawless start.
"He will come with us to the tournament and we'll see if he can play in the next match". We're going to appeal and hopefully, they'll take the match away.
On Saturday, Ronaldo struck twice.
In the 23rd minute, Marco Asensio slipped Ronaldo through into the right side of the penalty area, and the Portugal striker coolly dispatched a low shot past Sergio Rico at the near post.
"Just because you're very good, that doesn't mean you're the best, as you've had the bad luck of coinciding with the great Messi", he wrote on Twitter.