He became the first African to win the 400 m hurdles title at the Commonwealth Games in 1978, doing so in a time of 49.48 seconds after setting a lifetime best of 49.20 seconds in qualifying. He also led off the Kenyan 4×400 metres relay quartet to win a second gold in a Games record of 3:03.54 minutes.[1][2] That year he also secured a continental title at the 1978 All-Africa Games, succeeding John Akii-Bua, and won a relay bronze with Kenya.[3]
Kimaiyo won a second continental title at the 1979 African Championships in Athletics, where he was the inaugural 400 m hurdles champion. With the 4 × 400 m relay team he also helped his nation to the first ever title.[4] In addition to these titles, he was the winner of the hurdles at the East and Central African Championships.[5]
