Atletico have a game in hand over their rivals but the advantage is considerable and perhaps even insurmountable, even in December.
Barcelona are now 18 points adrift and arguably an irrelevance at the top after they were earlier held to a 2-2 draw away at Osasuna.
Sevilla, who last won the Spanish title in 1946, are the closest challengers, eight points back, and having played a game fewer.
Madrid, though, were ominously superior in a derby that had its occasional bad-tempered moments but was largely neutralised by the home side’s dominance at the Santiago Bernabeu.
Karim Benzema was passed fit enough to start and then, worryingly for Madrid went off again at half-time, but not before volleying them into the lead. Marco Asensio doubled the advantage in the second half.
There was never any sign of an Atletico comeback, with the home fans confident enough to cheer their team’s every pass in the 70th minute while some of Madrid’s defending late on was done at walking pace.
The 21-year-old Vinicius Junior was instrumental again, providing the assists for both goals, but it was the 36-year-old Luka Modric who ran the game, with the Croatian at his majestic, mesmerising best.
At one point in the second half the home crowd gave Modric a spontaneous standing ovation and he was so comfortable he even had time to applaud them back.
Atletico’s attacking talents all failed to fire. Luis Suarez started on the bench and came on when Madrid’s ascendancy was established. Joao Felix and Thomas Lemar replaced Antoine Griezmann and Yannick Carrasco at half-time but Diego Simeone’s attempts to shake life into his team came to nothing.
The first goal came from a mistake but Koke was in the middle of the pitch when his pass forward was cut out by Modric, the threat was not immediately obvious. But Casemiro played into Benzema and within seconds Vinicius was driving from the right and into the penalty area.
Atletico’s defence were dashing back with such intent they forgot about Benzema behind them, the Frenchman holding his position just inside the area for the cut-back. Vinicius found him with a floated pass and Benzema had time to send a perfect volley past Jan Oblak.
Griezmann tested Thibaut Courtois with a free-kick that was flying towards the top corner but otherwise Real Madrid were comfortable, their domination even provoking some petulance among Atleti’s players before half-time.
Simeone was perturbed as well because Griezmann and Carrasco were both substituted, with Felix and Lemar thrown on for the start of the second half. For Madrid, Luka Jovic replaced Benzema.
Felix went close soon after the restart but the changes made little difference to the balance of the game and just before the hour Madrid made it two. Jovic did well to feed Vinicius down the left and as the Brazilian approached the area he surprised everyone by playing right to Asensio, who slid his finish first time into the corner.