The Norway striker had a hat trick from scoring in the seventh, 10th and 11th minutes to the delight of the fans at Metropolitan Stadium in Madrid on Saturday.
His treble was the fastest ever in La Liga, according to Opta Statistics, which said the previous best was in 1941 of three goals in the first 15 minutes by Edmundo Suárez de Trabanco.
"I just had one of those days the ball just seemed to drop at my feet," Sorloth said. "Everything went in and they were good balls from my teammates."
Looking back on his first season with Diego Simeone's club, Sorloth said he was satisfied that he was getting more starts after mostly being a substitute for Julián Álvarez earlier.
"My teammates know I am going to be in the box," he said. "They don't even have to look, just cross it."
Sorloth got going when he volleyed in a cross from Pablo Barrios. He made it two with an angled shot just inside the far post, and Sociedad were left groggy when Jon Martín's clearance hit teammate Aritz Elustondo and fell for Sorloth to smash home.
Sorloth waited until the half-hour mark before he used one touch to control a pass by Samuel Lino before beating goalkeeper Alex Remiro to make it four goals. He went close to a fifth goal in the second half when he fired a volley off the woodwork.
Sorloth, who played for Sociedad from 2021-23, also scored four goals while playing for Villarreal last season in a 4-4 draw with Real Madrid.
Sorloth joined Cristiano Ronaldo, Lionel Messi and Luis Suárez as the only players to have more than one game of four goals in the Spanish league this century.
Atletico look certain to finish in third place. Sociedad are in 12th place.
Fifth-placed Villarreal got an 89th-minute goal from substitute Etta Eyong to open a four-point gap over Real Betis in their battle for the final Champions League spot.
Celta Vigo scored twice after losing Marcos Alonso to a direct red card and beat Sevilla 3-2 to remain in seventh.
Valencia scored thrice in the first half to ease past Getafe 3-0 as they continue to recover form as the season reaches its end. They had been in last place and are now 10th.
