Churchill Downs has announced the most famous horse racing event in the world -- The Kentucky Derby -- will be postponed from May to Sept. over the coronavirus scare.

It's the first time the race won't be run in May since 1945 ... when officials called off the event due to WWII.

“Throughout the rapid development of the COVID-19 pandemic, our first priority has been how to best protect the safety and health of our guests, team members and community," Churchill Downs honcho Bill Carstanjen said,

"As the situation evolved, we reached the difficult conclusion that we needed to reschedule. At no point did we ever consider canceling the Kentucky Derby.

The plan is to reschedule the race from May 2nd to Sept. 5 -- which just needs final approval from the Kentucky Horse Racing Commission. The KHRC is expected to give the thumbs up on Thursday.