Real Madrid was held to a 1-1 draw at home to Real Valladolid on Sunday (AEST), but Benzema was at least given a reason to crack a smile for his individual feat.
The former Lyon man netted a fine opener on the turn in the 82nd minute, finding the bottom-right corner from 18 yards.
However, it was ultimately not enough for the three points, as Sergi Guardiola converted just before the end to seal a shock draw for Valladolid.
Benzema has taken 10 years to reach the 150 milestone, but for a while it looked like he may never get near that number.
The striker's poor form in 2017-2018 had his future at the club in doubt, but he bounced back last term with 21 goals in LaLiga, a figure he has only exceeded once in his career.
His effort on Sunday (AEST) was his second strike in as many games for the new season, making him only the seventh player to reach 150 goals for Madrid in Spain's top flight.