Ezekiel Otuoma’s solitary goal for the power men handed Robert Matano his first defeat since he took over as Ingwe head coach early July.
AFC Leopards goalkeeper, Gabriel Andika was also handed a rude welcome by his former club, when he conceded an early goal despite Ingwe’s positive start.
Duncan Otieno gave Ingwe the first shot on target in the second minute but the stinging effort was saved by Stima goalkeeper.
Burundian, Alexis Kitenge came close to scoring his first goal for AFC Leopards in the 21st minute but his dangerous ball hit the cross bar. Ingwe continued to push for an equalizer but their effort could only be rewarded with a yellow card on Salim Abdalla, who was cautioned in the 43rd minute for a foul on a Western Stima player.
Stima took their slim lead into the break and held on until the final minute despite Matano making double substitution soon after resumption to pile more pressure.
Keziron Kizito replaced Whyvonne Isuzza while Samuel Ndung'u came in for striker Vincent Oburu, who is yet to score in the last three matches. Ray Omondi later came on for Kitenge in the 73rd minute but Stima held on to the advantage.
AFC Leopards have only won one of their last eleven matches and latest defeat leaves them with only 19 points from 17 matches.
Elsewhere, Chemelil Sugar played out to a barren draw with Thika United at the Mumias Complex Stadium.