LONDON — And then there was one.

Michael Phelps came up golden again on Friday, swimming his last individual race, the 100-meter butterfly. He has just his leg in the 400-meter medley relay left to swim in these Olympic Games - or any other, for that matter.

“I’m just happy that the last (individual) one was a win,” Phelps said. “That’s all I really wanted coming into the night.”

His gold medal in the 200 IM on Thursday marked the first time a male swimmer has won the same event in three straight Olympics. He duplicated that feat Friday in the 100 butterfly, winning his 17th career gold medal.

Saturday brings the last of a week of lasts: the Baltimore swimmer, now 27, is retiring from competitive swimming after these Games, but already his legacy can be found in the pool with him.

Call them the post-Michael generation, the young swimmers who - like him - swim big multistroke and multidistance programs, who have studied his races and adopted his playbook and now, as he leaves, are living proof that he has fulfilled his goal of elevating the sport.

On Friday, Phelps shared the stage with them: Chad le Clos, the 20-year-old South African swimmer who repeatedly watched Phelps’ races on his computer and whose only wish was to one day be in the same pool as him for a 200 fly, even if it was just a preliminary heat. Instead, he went on to beat Phelps on Tuesday night in that race by a fingertip, and on Friday tied for silver in the 100 fly to his idol’s gold.

There is Missy Franklin, the 17-year-old phenom who broke a world record in Friday’s 200-meter backstroke, adding to the two golds and one bronze she won earlier in the week. Franklin said she has watched Phelps at meets, marveling at - and trying to emulate - his calm despite his packed race schedule.

“What he’s done is incredible, and it’s helped people rethink the impossible, and rethink what they can do and how they can push themselves,” Franklin said. “He goes through so much every single day.”