In May 2023, at age 39, Zuckerberg made his competitive Brazilian Jiu-Jitsu debut at the BJJ Tour Silicon Valley tournament. Competing under the name Mark Eliott in the Masters (30+) featherweight division at 155 pounds, he demonstrated tactical composure and adaptability. In the no-gi division, Zuckerberg secured gold after a best-of-three series against the same opponent, winning two matches and losing one. In the gi division, he earned silver following a closely contested match involving an Ezekiel choke.