Ariarne Titmus stole the show in an elegant black dress during her special appearance with her boyfriend, Mack Powell, at the Derby Day. This appearance was her debut event following her retirement from swimming.Titmus' last competitive outing was at the Paris Olympics, and after a year of it, she announced her retirement from the sport. Recently she attended her first formal event as a former swimmer at the Derby Day on November 1. The former swimmer shared a few pictures of her in a Jimmy Choo black-colored bow-accent cocktail dress paired with white stilettos from the event on Instagram. She also uploaded a picture with her boyfriend, who wore a grey and black suit. The post's caption read:"Derby Day🖤" View this post on Instagram Instagram PostTitmus made her relationship public with her boyfriend, Mack, while they attended the Australian Open together in January 2025. She recently penned a message for him on her Instagram story along with a picture of them from their appearance at the Tiffany & Co. luxury store opening. The note read:"You are the greatest gift of all."Ariarne Titmus shared an emotional note while announcing her retirement from swimmingAriarne Titmus had an illustrious swimming career, with 10 world championship medals and 4 Olympic medals. The Australian announced her retirement from the sport after competing for over 18 years through a heartfelt note on her Instagram handle."Dear seven year old Ariarne, Today you retire from competitive swimming. 18 years you spent in the pool competing. 10 of those representing your country. You went to two Olympic Games and even better, you won!! The dreams you had.. they all came true. The friends you’ve made.. they’re for life. You achieved more than you ever thought you were capable of and you should be so proud," Ariarne Titmus wrote.Adding to this, she said that she is happy with her career and is excited for the future."You’ve just turned 25 and the time feels right to step away from swimming. The pursuit was unrelenting and you gave it every skerrick of yourself. You walk away knowing every stone was turned, no regrets. You’re fulfilled, content and happy.What’s ahead for you is exciting. New goals, more time with the people you love most and the chance to wholeheartedly put yourself, not your sport first," she added.In September, earlier this year, Ariarne Titmus enjoyed a hot-air balloon ride with her boyfriend, Mack Powell, as her pre-birthday celebration.