It didn't take Michael Phelps long to work on cementing his legacy as an Olympian. He was voted by teammates to be the flag bearer in the opening ceremony as he marched in the event for the first time.

At the pool, Phelps showed he wasn't in Rio just to be a mentor or for a final ride off into the sunset by just showing up to the games. He started with a gold medal in the men's 4x100-meter freestyle relay, which earned him his 23rd medal and his 19th gold medal.

Phelps even birthed his own meme during the games. While rival swimmer Chad le Clos of South Africa danced in front of him, Phelps had a look on his face that would have made Emperor Palpatine proud.

Just four years ago in London, le Clos beat Phelps to the wall in the 200-meter butterfly. It was a shocking defeat for him. He hadn't lost that race internationally in a decade.

It was Phelps who got the last word in their rivalry when he touched the wall first in the 200-meter butterfly in Rio, and le Clos finished fourth. The win was a historic moment in a career of historic moments for Phelps.

By earning the gold medal in the 200-meter butterfly, Phelps avenged his London loss, but at 31 years old, he also became the oldest individual gold medalist in Olympic swimming history.

He is the only male swimmer to win an individual event three times after winning the 200-meter butterfly in the 2004 and 2008 games. Phelps has also won the 100-meter butterfly and the 200-meter individual medley three times during his stellar career.

The win in the 200-meter butterfly gave Phelps a tie for most individual medals with Larisa Latynina, a gymnast from the Soviet Union, who had 14 medals. Of those 14 individual medals, 12 are gold medals.

Phelps wasn't done for the night, though; he also helped the U.S. win the 4x200-meter freestyle relay. The double in one night gave the swimmer his 20th and 21st gold medals in his career.

The 25 Olympic medals that Phelps has collected in the games is more than any other athlete in Olympic history. As his five-time Olympian career comes to a close in Rio, he will go down as one of the most dominant swimmers in the history of the sport.

Phelps made his Olympic debut during the 2000 games in Sydney at the age of 15—making him the youngest swimmer to make the U.S. team in nearly 70 years. He failed to reach the podium during his first trip to the games.

Four years later in Athens, Greece, Phelps won eight medals. He earned six gold medals and two bronze medals in the 2004 games, and a star was born.

It was at the games in Beijing that Phelps became a living legend. He finished a perfect eight-for-eight in events, as he took home eight gold medals in the 2008 games.

In London, Phelps slipped a bit, failing to medal in the 400-meter individual medley for the first time since 2000. He bounced back, winning six medals with four gold and two silver.

A lot has changed for the swimmer since his first Olympics. He has been involved in controversies such as being photographed holding a bong, and he is now a father with the birth of his son Boomer.

He has come out of retirement to compete in these games, and it seems unlikely he will make the team in four years. By the time the Tokyo Olympics take place in 2020, Phelps will be 35 years old.

But he still has a chance to make history. He has a chance to pass Latynina if he can medal in the 200-meter individual medley during tonight's events. It would give him his 15th individual medal and sole possession of first place.

See if Phelps can make history tonight on NBC, as coverage begins at 7 p.m. The final will take place during primetime.