Michael Phelps wins gold in the 200-meter butterfly during the Olympic Games on Tuesday in Rio De Janeiro, Brazil. He was edged out of a gold in the same race during the 2012 Olympics. (Jonathan Newton/The Washington Post)

Michael Phelps said he won back the title closest to his heart Tuesday, during an evening of pure gold for the top-medal-winning Olympic athlete of all time.

The 200-meter butterfly was the first race he swam at an Olympics, at Sydney, Australia, in 2000. It was also the gold that got away and the one he wanted back after losing by a fingertip at the 2012 London Games to South African Chad le Clos.

It hurt so much that Phelps made it his mission to exact revenge in Rio and win it one last time.

“Mission accomplished,” he said after claiming the 20th Olympic gold of his career. He then won his 21st by helping the U.S. team win the 4x200 freestyle relay.

Japan’s Masato Sakai ran second in the butterfly to collect the silver; Hungary’s Tamas Kenderesi won bronze. Le Clos finished fourth.

Phelps, left, added to his medal haul Tuesday night with a gold in the 4x200-meter freestyle relay. His relay teammates were Townley Haas, Ryan Lochte and Conor Dwyer. (Michael Dalder/Reuters)

Phelps has now amassed a record-setting 25 Olympic medals. But some of them count more than others.

“Just being able to see the number 1 next to my name again, one more time in the 200 fly, I couldn’t have scripted it any better,” he said.

— Reuters