Real —- who have won 29 of those 38 matches —- are one short of equalling a best-ever run by a La Liga team.
James Rodriguez scored twice as he made a rare start in the absence of the rested Cristiano Ronaldo.
Raphael Varne also headed home to put Real firmly in control, with the second leg in Seville on Jan. 12.
An excited Coach Zinedine Zidane said at the end of the match: “I don’t know if it’s the best since I arrived, they were 45 very good minutes, good spells of football and with intensity. We worked on that and we got it. When you start the game like that and you score, it sets things up for the rest of the game”.
“It’s obvious that starting the year like this is very important. It is what we wanted and we prepared for it. We wanted to put a lot of intensity in at the beginning and score and it couldn’t have gone any better. We must continue like this, we know that it’s a long road and that after every game everything is questioned again”.
Zidane also gave praise to Rodriguez: “He’s had a good game. He’s scored two goals and done an important job, like everyone else. I’m happy with how he played and that’s the same for everyone else”.
The second leg may now appear a formality amid a hectic schedule that could see Real play 21 times in 11 weeks.
The News Agency of Nigeria (NAN) reports that in this match Madrid started a second consecutive home game without any of their first-choice front three.
They left Karim Benzema on the substitutes’ bench, while Ronaldo rested and Gareth Bale was sidelined with a long-term ankle injury.
Rodriguez had previously said he would consider his future in January after playing a minor role so far this season.
But he made the most of a rare start by scoring a spectacular long-range opener and adding his second with a penalty kick after Luca Modric was fouled by Mariano.
Real Sociedad also took a huge step towards the last eight with Willian Jose, Carlos Vela and Mikel Oyarzabal scoring in a 3-1 win over Villarreal.