Struggling Eibar was the first of three visitors to Estadio Alfredo Di Stefano in succession, with games against Liverpool and Barcelona set to go a long way to defining Madrid's season.
Los Blancos were not tested on Sunday (AEDT), though, frustrated only by offside calls and their own finishing either side of Marco Asensio's 41st-minute strike before Karim Benzema made sure 17 minutes from time.
Although Atleti and Barca – now third behind Zinedine Zidane's side – are both still to play this weekend, Madrid's title rivals will do well to find opponents as accommodating as Eibar.
An awful blind pass from Alejandro Pozo sent Benzema clear three minutes in, but the striker delayed before shooting and allowed Marko Dmitrovic to make a brilliant right-handed save.
Benzema was quickly denied again, this time by the offside flag after nodding in Marcelo's cross at the far post.
Asensio saw a wonderful free-kick bounce away off the crossbar and then joined Benzema in having a breakthrough goal struck off, his exquisite flick nutmegging Dmitrovic but drawing the attention of VAR (video assistant referee) again for offside.
Fortune soon found Asensio's favour, however, as he charged onto Casemiro's pass and slipped while shooting, only for his effort to clip his standing foot and beat Dmitrovic.
A second-half storm briefly threatened to derail Madrid, notably when Lucas Vazquez's backpass picked up pace on a slick pitch and required a desperate lunge from Thibaut Courtois to divert it to safety.
But after falling foul of the flag for a third time – Casemiro disappointed by team-mates standing in Dmitrovic's line of sight – Benzema wrapped up the result with a downwards header from substitute Vinicius Junior's fine centre.