The Mailmen came into the match in desperate need of a victory to boost their chances of surviving in the league.
However, that was not going to be the case for the visitors as Gerson Likonoh and Francis Nambute hit a double each, with the other two Rangers goals coming from Brian Osumba and Cavin Odongo.
The consolations for the visitors were scored by Brian Nyakan and Amani Kyata.
MKU soach Melis Medo has every reason to worry considering the fact that the team is glued to the bottom of the table.
The Robert Matano-led Tusker FC defeated Kariobangi Sharks by 2-0 at the Kasarani Stadium. After a goalless first half, the Brewers scored through Timothy Otieno and Boniface Muchiri in the 64th and 73rd minutes respectively.
At Moi Stadium Kisumu, Bandari FC defeated hosts Western Stima 3-1 in a game which both teams ended with ten men. Samuel Odhiambo and Fred Nkata were dismissed by the referee in the 45th and 85th minutes respectively.
Kakamega Homeboyz reached 38 points on the KPL table after winning against Vihiga United by a solitary goal. The visitors were the better team in the entire game, but the closest they came was when they hit the crossbar through Kelvin Muhanji.
The Nicholas Muyoti-led side, however, managed to get the only goal in the 16th minute through striker Allan Wanga, who had missed a penalty earlier on, to ensure they walk home heads high.