The bankers took their point tally to 14, same as Bidco United, Western Stima, Kibera Black Stars and Kisumu All Stars following the victory at Camp Toyoyo on Saturday.
The victory was a second consecutive win for KCB who were playing without the head coach, John Kamau who is away on national team duties.
Kennedy Owino gave KCB the lead in the ninth minute before Zeka Wakoli cancelled the hosts lead with an equalizer a few minutes later.
Michael Osundwa doubled KCB’s advantage minutes to the break before Dennis Nganga sealed all the three points with a cool free kick, just outside the box.
KCB’s win adds to a tight race in the NSL that leaves the top eight teams separated by only three points.