Karim Benzema reached 30 LaLiga goals in 2021 with a first-half double as Real Madrid edged past Athletic Bilbao 2-1 to extend their lead at the summit.
Benzema's brace inside seven minutes on Wednesday quickly helped atone for Madrid's goalless draw with lowly Cadiz last time out.
Oihan Sancet halved the deficit in a frantic opening at San Mames, but the hosts rarely troubled Thibaut Courtois after the interval as Carlo Ancelotti's side navigated the contest to seal the three points.
Victory means Madrid boast an eight-point advantage over second-placed Sevilla heading into 2022 and a 17-point lead over defending champions Atletico Madrid, who were defeated by Granada.
Madrid struck first when Benzema expertly whipped into the bottom-right corner following Toni Kroos' offload, before the France striker added a quickfire second as he rolled past Julen Agirrezabala – Madrid scoring twice in the first seven minutes of a top-flight game for the first time since 1994.
11 games unbeaten
Sancet responded by crashing a strike from the edge of the area in off the left post, with Unai Vencedor then wastefully curling just over as Athletic searched for an equalizer.
Real Madrid's Nacho (R) and Ferland Mendy celebrate their side's second goal. Photo: Edu Del Fresno/dpa.
Kroos sliced harmlessly off target from range after the interval, while Inaki Williams fired narrowly wide and Raul Garcia blasted over as the game headed towards what promised to be a nervy ending.
Substitute Nico Williams then failed to slide under Courtois as Athletic, despite their best efforts, were unable to find a late leveller as Madrid held on for a narrow victory to make it 11 LaLiga games unbeaten.
Madrid return to action in the new year as they travel to Getafe on January 2, while Athletic visit Osasuna the day after.
