The former Sony Sugar man got 19 votes while Kagere and Juma garnered 15 and 13 votes respectively.
Coach Mike Mururi lauded his entire team for a splendid performance this season.
"When I arrived here last season the club was new to me and I was new to everything.
"But this year I've had a better grip and the players bought well into my philosophy. I shall try my best to hold on to the squad and make additions for a title charge next year," he said.
The team also got Sh50,000 for their contribution, a quest they had never achieved since the inception of the monthly award system in 2014.
Wanjala is the sixth recipient this season after Nzoia Sugar’s Brian Omondi, Stephen Waruru (Ulinzi Stars), Ernest Wendo (Gor Mahia), Michael Madoya (Zoo Kericho) and George Odhiambo (Gor Mahia) who won from March in that order.