Joseph Baena's professional bodybuilding career is off to a swinging start.Baena, 28, took home first place at the International Natural Bodybuilding Association's (INBA) Iron Gladiator competition in Southern California.When asked why he chose to compete through INBA, Arnold Schwarzenegger's son admitted he was "excited" to show off his hard work."[It's] my second competition ever," Baena said on social media before the event. "We're ready for the debut and excited to get things going."ARNOLD SCHWARZENEGGER'S SON DOMINATES BODYBUILDING DEBUT WITH MULTIPLE FIRST-PLACE WINSHe added, "They just seem like the most reputable natural federation, and so I wanted to be a part of something like that ... I wanted to test them out.For his Iron Gladiator win, Baena wielded a silver sword and a helmet while posing on stage in black swimwear.KATHERINE SCHWARZENEGGER PRATT SAYS SHE’D LEAVE HOLLYWOOD BUT ONLY IF HER FAMOUS FAMILY GOES TOOLast weekend, Baena took followers through the competition flow as he prepped to show off his hard work to judges before earning first in the Men’s Open Bodybuilding Heavy Weight Class, Men’s Classic Physique True Novice, and the Men’s Classic Physique Novice.APP USERS CLICK HERE TO VIEW POSTHe also took home second place in the Men’s Classic Physique Open Class C."Tanned up and checked in! Ready for tomorrow’s show," Baena wrote in a carousel of behind-the-scenes images.CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTERHe thanked his friends and family for the sweet messages, but admitted there was still work to be done.APP USERS CLICK HERE TO VIEW POST"Time to do it again on Saturday," he wrote over a flexing image from the stage in Colorado. The event, which is a national qualifier, is also part of the NPC natural athlete pathway to the Olympia.WATCH: ARNOLD SCHWARZENEGGER TRAINS LOOKALIKE SON JOSEPH BAENA AT GYM AS BODYBUILDING BUZZ GROWSSchwarzenegger won seven Mr. Olympia titles throughout his bodybuilding career, set a record for six consecutive wins, and was the youngest-ever winner in 1970 when he was 23 years old.Last week, Baena shared a look at his training regimen with the "Kindergarten Cop" actor coaching him on the sidelines. "You have to shock the muscles!" he captioned a snap with his famous bodybuilder father.In a video obtained by Fox News Digital, Schwarzenegger carefully adjusted Baena’s positioning to ensure optimal muscle growth.LIKE WHAT YOU’RE READING? CLICK HERE FOR MORE ENTERTAINMENT NEWSBaena has been carving out his own path — from acting roles, including the 2024 action thriller "Gunner," to landing a Men’s Health cover — while navigating inevitable comparisons to his father."It's been a huge growth year of me finding out who I am and really being secure … confident … no matter what the challenges are, what the comparisons are," Baena previously told Fox News Digital.Baena added, "The message that I wanted to get across was, there’s a lot of people out there with very accomplished parents … and it’s scary. It’s scary to get compared to these giants and to have the feeling like you need to live up to these expectations."