Russia's Korotyshkin qualified eight in 50.26 to secure his favourite lane eight in the final.
2012 Olympic silver medallist Korotyshkin is realistic about what awaits, saying: "I'm happy about my semi-final time. I'm not ready for records. I've achieved my minimum in qualifying but finals are quite unpredictable."
Evgeny Korotyshkin - Photo credit: Giorgio Scala/Deepbluemedia
What about Le Clos? "Before the 100m butterfly he had just won the 200m freestyle finals and so he seems ready to beat my record."
"For me is it a big honour to have held the record since 2009. In my opinion, any records are there to be beaten to give other swimmers new hopes for their future in the sport."
Korotyshkin still has the satisfation of the memory of the prize money for the 48.48sec record he set in Berlin on November 15, 2009.
He said: "I still have my diploma, I got $10,000 prize money, and, well ... bought a new sofa and a TV-set."
Now 31, Korotyshkin is a specialist in 50m and 100m butterfly and is a six-times world record-holder.
He won World Championship bronze in 2003 and was a short-course champion in both 2008 and 2010 as well as bronze medallist in 2010.