Arnold Schwarzenegger's son has won his first bodybuilding competition.

The former Mr. Universe's offspring Joseph Baena - who he has with his former housekeeper Mildred Patricia Baena - clinched first place in a number of categories at the NPC Natural Colorado State competition, including the Men's Open Body Heavy Weight Class, Men's Classic Physique True Novice and Men's Class Physique Novice, and also came second in Men's Classic Physique Open Class C.

Joseph, 28, shared several photos from his bodybuilding debut on Instagram and wrote: "Mission Accomplished! [gold medal emoji]

"NPC Natural Colorado

"Men's Open Bodybuilding Heavy Weight Class - 1st [gold medal emoji]

"Men's classic Physique True Novice - 1st [gold medal emoji]

"Men's Classic Physique Novice - 1st [gold medal emoji]

"Men's Classic Physique Open Class C - 2nd [silver medal emoji] (sic)"

Terminator star Arnold began his career as a bodybuilder and won Mr. Olympia title seven times and Mr. Universe five times, but gave up competing in 1980.

Joseph hasn't always been in good shape and previously admitted he was dropped from his high school sports teams because he couldn't "keep up" with his peers.

He wrote on Instagram in July: "People sometimes forget that I used to be chubby in high school. I got cut from my basketball and soccer team because I couldn't keep up with the other kids.

"Swim didn't have tryouts thankfully and completely changed my life forever. That was my introduction to Fitness and training."

And Joseph has previously told how he was bullied because of his weight when he was young.

He told People magazine back in 2022: "I was bullied when I was a kid, elementary, middle school, and not really in high school, but I just felt like an outsider in high school at the beginning.

"I was really overweight from the end of elementary school into the beginning of high school.

"It was my closest friends that were the ones that bullied me the most and made fun of me for being overweight and all these kind of things.

"So, that was really a big struggle for me in finding myself and figuring out and creating that ambition to change my weight and my physique."