Madrid's team is at breaking point such is their collection of injuries but Courtois' one-man defence proved enough to earn what might be a worthwhile draw.
Marcos Llorente and Angel Correa both scored doubles in the contest which, given Real's draw and Barcelona's participation in the Copa del Rey final, allowed them to open up a three-point gap again at the top.
And Sevilla have ensured this continues to be a four-horse race. Their goals from Fernando and Youssef El-Nesyri in the first half secured victory at Real Sociedad and put them on 64 points for the season, six back of Atletico Madrid.
At the opposite end of the table, Eibar's thumping at the hands of Atletico makes them look increasingly doomed, but the other two relegation places are very much up for grabs.
Valladolid were due to play Athletic, who were on cup duty, meaning they had a free week and remain on 27 points, level with Huesca and Alaves, the latter winning a crunch clash against the former to give their chances of survival a real boost.
LA LIGA STATISTICS: