Michael Phelps

You aren't supposed to cry upon winning your 20th gold medal. At least, that is what us normal people can say in theory. No one has reached that plateau other than Michael Phelps (in fact, no one has gotten to 10 gold medals other than Phelps).

But there was Phelps on Tuesday, winning perhaps his most emotional gold medal and sobbing afterwards.

As for the backstory, the 200-meter butterfly is arguably Phelps' trademark event. In 2000, it was the only event 15-year-old Phelps qualified for in Sydney. He finished fifth.

Phelps followed by setting an Olympic record in 2004 for the gold. In 2008, he won gold again, breaking his own 2007 world record. But in 2012, Chad le Clos slipped past him by five-hundredths of a second, and Phelps left London with a silver medal.

Phelps retired in 2012. Although he came out of retirement in 2014, Phelps was suspended for the 2015 world championships after a DUI. When Phelps and le Clos stood up on the blocks Tuesday, it was their first major meeting since London. And the drama peaked after le Clos shadow-boxed in front of a hooded Phelps before the semifinal.

In the pool, Phelps got his redemption. It was even sweeter than that. Phelps not only got his gold back, but le Clos finished fourth, off the podium. And Phelps took the time to celebrate in the pool on his familiar throne.

Phelps' 3-month-old son, Boomer, was feeling his dad's beatdown of le Clos.

Michael Phelps

Even on gold medal No. 20, Phelps let his emotions get the best of him on the podium. He cried during the national anthem.

After all the le Clos beef, Phelps raising his arms in the pool (a la Lilly King) and his tears of joy, Phelps dove right back in the water for the 4x200 freestyle relay. He anchored the team to an easy gold medal, Phelps' fourth all-time in the event.

The win did not come without a touch of drama. Phelps actually broke his swim cap moments before his leg.

Phelps borrowed teammate Conor Dwyer's cap and turned it inside out. A little wardrobe malfunction would not stop the GOAT from sealing the deal.

Phelps is three-for-three in Rio events. His 21 gold medals are an Olympic record, as are his 25 total medals. Phelps is back in the water Wednesday morning for his 200-meter individual medley heat. He is a three-time defending gold medalist in the event.

More Olympics:
-- 7 Sports You Probably Don't Know Are Olympic Events
-- Best U.S. Olympic Athletes To Follow On Instagram
-- Lilly King And America Celebrate 'Clean' Gold Medal

-- Follow Jeffrey Eisenband on Twitter @JeffEisenband.