Tokyo Olympics: Australian swimming coach Dean Boxall explodes in celebration after Ariarne Titmus' gold medal swim

Australia's Ariarne Titmus lit up the pool with a stunning victory over Katie Ledecky at the Tokyo Games on Monday, but when it comes to celebrations, it was her wide-eyed, hip-thrusting coach Dean Boxall who deserved an Olympic gold.

As Titmus reached for the wall to dethrone her American rival in the 400m freestyle, Boxall burst into a frenzy of exuberant celebrations, punching the air and darting around the spectator gantry.

While the 20-year-old Titmus was being congratulated by her fellow swimmers, the crowd were mesmerized by Boxall as he leaped in the air, tore off his mask and screamed ecstatically, headbanging with his surfer-like hair tumbling around him.

"It just came out ... When I saw the race unfolding I couldn't keep it in," he told Australia's Seven Network. 

He said he started frantically shaking the barrier just like his childhood hero, American wrestler 'The Ultimate Warrior', used to do to the ring.

"Arnie executed it to perfection. So when I saw it starting to build, I thought 'here we go'," he said. 

"I need to apologise, I took my mask off by mistake and it just ripped. I just lost it in the moment."

Titmus had nothing but praise for her coach, whose antics played out on television globally and went viral on social media.

"He means everything to me," Titmus said. "We didn't discuss what I wanted to do in the pool. It was more of a 'have fun' moment. I love you. Have fun."

Nearby staff in the arena jumped to avoid Boxall as he lurched unpredictably and it took the embrace of a fellow Australian team member to calm him down.

"I have seen little snippets of it," Titmus said of Boxall's reaction. "That's just the way Dean is, he is just passionate about what he does, he becomes so animated. For him as much as it is for me. He puts 100 percent into being a swimming coach."

Five-times Olympic gold medallist Ledecky held a good lead in the early part of the race, before Titmus began to reel her in and then burst out of the final turn to power her way to victory.

Titmus said she became emotional during the medal ceremony knowing her coach was watching and what it meant to him.

"It was actually hard to contain it," Titmus said.

"I could see Dean on the other side bawling his eyes out. You don't really see that often, so, that made me want to tear up."