
The pragmatic rather than spectacular win keeps Real seven points clear of second-place Barcelona, who beat Racing Santander 1-0 late Sunday at home.
Barca didn't play well and needed a stroke of good fortune to score the only goal in the 31st minute.
An Andres Iniesta corner from the left was clumsily sliced toward his own goal by Santander defender Cesar Navas, allowing Thierry Henry to head the ball home at ease.
Sixth-place Santander threatened to equalize in the second half, but Barca held on without too many problems.
Earlier Sunday, Real had their usual heroes to thank for their derby win: Raul Gonzalez, Ruud Van Nistelrooy and Iker Casillas.
Raul opened the scoring in the very first minute, Van Nistelrooy made it 2-0 just before halftime, and keeper Casillas kept the hosts at bay with several sharp saves.
Real now have 50 points from 20 games and are well placed to clinch their 31st Liga title.
"We were a little bit sharper than them in both penalty areas," was the judgement by Casillas to radio station Cadena COPE.
Indeed they were. Bernd Schuster's team, true to form, were incisive in attack and mean in defence.
Atletico, in contrast, were blunt in attack and sloppy in defence. That sloppiness was evident in the very first minute, when defender Pablo Ibanez nervously gave the ball away to Real winger Robinho, who calmly centred for Raul to open the scoring.
The early goal forced Atletico to attack and allowed Real to soak up the pressure and play on the break.
Thiago Motta headed against the Real crossbar in the 30th minute. Ten minutes later, Casillas pushed a shot from Sergio Aguero onto the woodwork.
In the 41st minute, Van Nistelrooy, against the run of play, made it 2-0 with his left foot after the Atletico defence had failed to clear a corner from Wesley Sneijder.
Atletico continued to come forward in the second half but were foiled time and again by Casillas, in the best form of his career. At the other end, Van Nistelrooy and Robinho squandered good chances to increase Real's lead on the break.
Real now have 50 points from 20 games, while Barca have 43. In third place on 38 are Villarreal, who thrashed crisis club Valencia 3-0 Saturday.
Earlier Sunday, Espanyol squandered a good chance to retake third place by losing 2-1 in Valladolid, where Joseba Llorente was the two- goal hero.
His first goal was put away after just eight seconds, the earliest goal in La Liga in more than two decades.
The defeat pulls Espanyol down to fifth with 36 points, one point below fourth-place Atletico.
In sixth place, four points behind Espanyol, are Santander.
Valladolid are now joint seventh with Valencia after their defeat of Espanyol.
Sevilla are ninth after losing 3-2 Saturday in Getafe. In 10th place now are Almeria, who scored a late win 1-0 over troubled Deportivo Coruna.
Deportivo are now second from bottom with just 18 points, ahead of only doomed Levante. The defeat in Almeria will almost certainly mean the sack for embattled coach Miguel Angel Angulo.
Four points above Deportivo on 22 points are four teams determined to avoid relegation: Rercreativo Huelva, Betis, who drew 1-1 in Seville, Murcia, who lost 3-1 in Zaragoza, and Athletic Bilbao, 2-0 losers at Osasuna.
By Duncan Shaw, dpa