Olympic Games, London, Day 6 semi-finals:
Men's 100m Butterfly Semi-final:
It feels good to make history - and just after the medal ceremony for the third consecutive 200 IM Olympic gold that will have his name writ large in the history books - the semi-final of the 100 butterfly must have seemed like a walk in the park.
Steffen Deibler (GER) swimming next to him in lane 1 gave it a shot on the front end of the race - touching in 23.69 at the 50. But Phelps appeared to have wings on the second 50 and dominated the field easily to win the first heat in 50.86.
That meant there was a job to do in heat 2 - two in fact - as Chad le Clos (RSA) - the young man who denied Phelps the gold in the 200 - made another date with the Greatest for the final.
But American-born Milorad Cavic, swimming for Serbia in his fourth Olympics, also has a score to settle from Beijing 2008 - when he was touched out for the gold in this event by Phelps in a fraction (.01) of a second so small that his apparent win was eclipsed by Phelps' tactical and technical superiority.
Cavic was out in 23.56 to the 50 - with le Clos trailing behind. But the South African has certainly honed his racing skills next to the best, and after a PB this morning, came back on the semi-final heat to better t again and touch first in 51.42. Tyler McGill of the USA reached in for second in 51.61, and Cavic will have to rethink the touch again for the final after posting 51.66.
The line-up for the final has defending champion, world and Olympic champion Phelps serenely in first (50.86) - followed by le Clos, and McGill, with Cavic in 4th.
The final was locked down at 51.85 by Evgeny Korotyshkin of Russia.