Karim Benzema’s last-gasp effort in an enthralling contest saw Zinedine Zidane’s side reach the 40-game mark without defeat.
They are now clear on their own at the top of that particular Spanish roll of honour, having edged ahead of their eternal rivals from Camp Nou.
Barcelona went 39 games unbeaten between October 2015 and March 2016, as they swept to La Liga and Copa del Rey crowns.
They collected 32 victories and seven draws during that run, before Real brought it to an abrupt halt with a 2-1 Clasico victory.
40 - Real Madrid have surpassed the best ever unbeaten run by a La Liga side in all competitions (30W 10D). Legend pic.twitter.com/Gj3hQYlxG7— OptaJose (@OptaJose) January 12, 2017
Real’s run is slightly less impressive than Barca’s in terms of games won and goals scored, with 30 wins and 10 stalemates played out.
They have also netted 115 times, compared to 122 plundered by the men from Catalunya in their run.
Barca also conceded just 23 goals in 39 games, while Real have been breached 39 times in their record run.
The capital outfit are, however, now the pick of the Spanish crop and remain on course for multiple major honours this season – having progressed to the quarter-finals of the Copa del Rey on Thursday while also sitting top of the La Liga standings and through to the last 16 of the Champions League.