Roper, just 12, sprinted home in 12.1 seconds to eclipse the 12.4 clocked by Martin Giraud back in 1990, 12 years before he was born.
His time improved on the 12.49secs he clocked when taking the silver medal in the Surrey championships at Kingsmeadow in May, and the 12.4secs he posted at the last Ebbisham League meeting at Walton in June.
He almost made it a record-breaking double as he stormed to victory in the 200m in 25.5secs, just one-tenth of a second slower than the record Giraud set, also in 1990.
It sliced two-hundredths of a second off the time he posted in taking the silver medal in the Surrey championships.
His times rank him fourth in the UK in his age group in the 100m this summer and seventh in the 200m.
Another Hercules Wimbledon winner at Coulsdon was Phillip Danbinski who took the 100m and 400m B, and was second in the 200m A race.