Reacting swiftly after going behind, a cut back from Thomas Omole who disposed Rangers goal scorer Ochieng, was finished by Ogam who tied the scores at 1-1 in the 33rd minute after beating Bixente Otieno in goal.
Four minutes later, Thomas Teka gave the brewers the lead after finishing off a corner delivered by Dennis Wanjala as Tusker went to the break leading 2-1.
In the final half, Rangers came out more aggressive but could not match Tusker's confident defending in the early stages of the second half.
While Rangers looked for a life line with an equalizer, Tusker were pushing for a game killer, a gift that came to the brewers rather unlikely when Ranger keeper Otieno saw red in the 78th minute for bringing down goal-bound Omole outside the box.
With the numerical advantage, Tusker sealed the win in the 86th minute when Charles Momanyi rose higher to head home Yusuf Mainge's cross for 3-1.
The win lifted Tusker to joint top of the standings alongside KCB with 27 points albeit with a game in hand over the bankers. Rangers remain bottom of the table after the defeat.