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.
Sancet responded by crashing a strike from the edge of the area off the left post, with Unai Vencedor then wastefully curling just over as Athletic searched for an equalizer.
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 leveler as Madrid held on for a narrow victory to make it 11 LaLiga games unbeaten.
What does it mean? Madrid title charge marches on as unbeaten run continues
Ancelotti's side frustratingly saw their 10-game winning run across all competitions abruptly ended in a goalless draw with Cadiz, but Madrid responded excellently to ensure a healthy eight-point lead heading into LaLiga's mid-season break.
Athletic, who are winless in their past 14 top-flight meetings with Madrid, proved fierce competition for the visitors but could not stop Los Blancos from continuing their unbeaten run in all competitions that stretches back to early October.
Brilliant Benz in cruise control
Benzema's first-half double were his 29th and 30th goals of 2021 in LaLiga. Since the turn of the century only four players – excluding Lionel Messi (nine times) and Cristiano Ronaldo (seven) – have reached the 30-goal milestone in the competition.
Indeed, the France international joins esteemed company with Luis Suarez (2015 and 2016), Radamel Falcao (2012) and Ronaldo Nazario (2003) the others to achieve the feat and the Madrid striker now also has 17 goals in 26 games against Athletic across all competitions.
Muniain masterclass in vain
Iker Muniain delivered a creative masterclass on the left wing against Lucas Vazquez, though the Athletic veteran's showing eventually proved in vain.
The Spain international created a game-high four chances – two more than any other player on the pitch – as he produced a delightful attacking display for the home crowd.
Madrid returns to action in the new year as they travel to Getafe on January 2, while Athletic visit Osasuna the day after.