The result moves Police onto 27 points in third place on the log, four points behind leaders Nzoia Sugar who thrashed Kariobangi Sharks 3-1 in another mid-week fixture.
Kenya Police FC made all the early running and created several chances in the opening 20 minutes, with Elvis Rupia, Duke Abuya and Clifton Miheso guilty of spurning good scoring opportunities.
The Makarao continued to push hard in attack, but they found Nairobi City Stars goalkeeper Jacob Osano a tough man to get the better of, with both Abuya and Rupia denied by sharp saves in the latter part of the first half.
City Stars then put together a couple of good chances, especially in the 39th minute when a ball ran right across the penalty area to find Ezekiel Odera, who sliced an effort-high febrility instead of testing goalkeeper Job Ochieng.
Kenya Police, alarming lack of defensive organization, was exposed a minute before halftime, with a brilliant pass into space from Kelvin Etemesi allowing Ezekiel Odera to sprint in behind the center-backs and bury a low shot inside the net to put City Stars 1-0 up.
Police made a change at the start of the second half, sending on Alvin Mageni in place of Clifton Miheso, but it was the Simba wa Nairobi who continued to look the likelier scorers and saw a missed chance from Peter Opiyo in the opening minutes after the restart.
Police created the first clear chance of the second stanza in the 53rd minute when Harun Shakava picked out Patilah Omotto in the penalty area. Still, the midfielder’s effort was straight at Jacob Osano.
Three minutes later, Keneddy Onyango played a teasing cross from the right that striker Ezekiel Odera could not turn home from close range, much to the frustration of the vocal home support.
Kenya Police never lost hope as they hit the back of the net to make it 1-1 with a good finish from Alvin Mageni.
Two minutes later, the second-half substitute then beat his marker and pulled the trigger, and his attempt went into the back of the net, beating Osano.
Job Ochieng hand again in the 73rd minute to deny Peter Opiyo from point-blank range - the City Stars midfielder had a frustrating day in front of goal, repeatedly getting himself into good scoring positions, only to fluff the finish.
Kenya Police were able to defend their slender lead in the game's closing stages, and ultimately, they emerged 2-1 winners of the day.