On Tuesday night, Michael Phelps won gold for the 4x200m freestyle relay at the Rio Olympics.

But it’s wasn’t your typical gold medal. It was his21st. It was his 21st Olympic gold medal.

Individually, he’s won 12.

As the greatest swimmer of all time, Phelps is particularly aggressive in the water. He’s like a wild alligator thrashing through the pool, beating his opponents as though his life depended on it.

#BREAKING Michael Phelps claims his 20th Olympic gold medal in 200-metre butterfly. @7olympics pic.twitter.com/kOwqqhLGbJ

— 7News Yahoo7 (@Y7News) August 10, 2016

When he won his 20th race in the 200m Butterfly final earlier on Tuesday, he held up his hands, gave his now-famous finger wag, and egged on the roaring crowd in the stadium while sitting on the lane rope.

But it wasn’t his post-race celebrations in the pool that got our attention.

It was the moments after, when he walked over to his fiancee, mother and seven-week-old son in the crowd, took his child in his arms, and kissed him.

Phelps’ partner Nicole Johnson was holding little Boomer with tears in her eyes, while Phelps’ mother held the back of her sons head and beamed with pride.

“Hey Dad. You ROCK!” – Probably what Boomer was thinking. #Rio2016 pic.twitter.com/5Jqf7jOsSH — NBC Olympics (@NBCOlympics) August 10, 2016

It was a rare emotional moment from the Olympian, who is currently being heralded for his physical power and strength.

It’s important, too, to see him share such a special, career-defining event with the people who no doubt support him through the rigorous training hours and the stress of being a world-class swimmer.

And years from now, when people talk to Boomer about the time his dad won his 20th gold medal, he can be assured that it was it was him, and not the countless screaming fans, his dad reached for to celebrate.

Perfect ending to a perfect race! ❤️ pic.twitter.com/0mImMviHQF — U.S. Olympic Team (@TeamUSA) August 10, 2016

Listen to Mia Freedman’s interview with Leisel Jones about the life of a professional swimmer.