Gor Mahia and AFC Leopards suffered an identical 1-0 defeat to their respective opponents in yesterday's SportPesa Premier League matches ahead of this Sunday's Mashemeji derby at Kasarani.
KCB beat Leopards in Machakos to complete a double over Casa Mbungo's men as Nzoia Sugar ended K'Ogalo's 21-game unbeaten run at Mumias Sports Complex.
Hansel Ochieng's 34th-minute goal is all that Nzoia needed to condemn Gor to their fourth defeat of the season.
It was the same situation at Kenyatta Stadium when Kennedy Owino struck on the stroke of halftime to silence Leopards.
Despite the loss, K'Ogalo are still at the top of the table with 66 points, ten more than second-placed Sofapaka, while Ingwe are ninth with 39 points.
Both teams fielded weakened squads, resting their key players for this weekend's return leg.
Mbungo rested the trio of David Ochieng, Whyvonne Isuza and Soter Kayumba to avoid suspension due to card accumulation while Paul Were missed his second consecutive match after failing to travel to Awendo for their rescheduled barren draw against Sony Sugar.
"It's not the result we expected ahead of the derby. It's not because we rested our key players. We just didn't make good use of our chances, especially in the second half. But that's now history, our focus is on Sunday's game," Mbungo told Standard Sports.
While his derby counterpart Hassan Oktay rested Harun Shakava, Joash Onyango, Kenneth Muguna, Francis Kahata and Philemon Otieno as the trio off Samuel Onyango, Jacques Tuyisenge and Lawrence Juma came off the bench in the second half.
Leopards could have taken the lead in the ninth minute but Robinson Kamura's long-range free-kick was thwarted by the goalkeeper Joseph Okoth.
But the bankers punished AFC in the 37th minute when Owino latched on Michael Kibwage's long-range pass then capitalized on Kamura's defensive error to beat their keeper Ezekiel Owade.
Substitute Vincent Oburu nearly restored parity on the hour mark but the keeper came off the line to deny him before Musa Saad fluffed his shot at the edge of the box.
Kamura then saw his free-kick deflected for a corner kick before Oburu missed a golden chance in the six-yard.
In other matches, Zoo revived their relegation survival chances after rallying to beat Western Stima 2-1 in Kericho.
The victory saw the 16th ranked Zoo take their points tally 28 points, three points above the drop zone.
Sony Sugar overcame visiting Kariobangi Sharks 2-0 in Awendo.
Sony Sugar 2-0 Kariobangi Sharks
KCB 1-0 AFC Leopards