It's become one of the biggest athletics events of the year in Chichester - and 2017 saw a vintage renewal.
Chichester Runners and AC first staged the Corporate Challenge 25 years ago when relatively-small numbers of adults turned out to do battle round a city-centre course.
Fast forward to the present day and you'll find North Street and surrounding streets transformed for three Wednesday evenings each February and March.
Each race evening begins with something of a cavalry charge of primary school children vying for their race honours. That's followed by senior school children, then the A race for the top senior runners and the B race for those not expecting such quick times.
Numbers have grown each year and many athletes have started off running for their primary schools then graduated over several years into the seniors' races.
Our video, above, captures something of the wonderful atmosphere generated by the event, as much down to the people who line the streets to cheer on family and friends as to the runners themselves.
Look out for the 2018 series coming soon in the Observer and on this website