Nzoia Sugar stretched their unbeaten run at their impenetrable Sudi Stadium to 11 matches after narrowly seeing off defending champions 1-0 in a top of the table FKF Premier League match played in Bungoma on Saturday.
James Kibande's spot kick in the 21st minute was enough to hand the Salim Babu led side their 14th win of the 2022-2023 season.
The victory also saw Nzoia close the gap between them and Tusker to three points with eight games left until the end of the season.
Nzoia are third on 51 points as Tusker dropped second on 54 points. Record Kenyan champions Gor Mahia moved top of the standings after edging out Kenya Police 1-0 at Kasarani Stadium.
Nzoia Sugar have won five of their 11 matches played at Sudi Stadium, drawing six in the process.
Elsewhere, Rooney Onyango scored the lone goal as relegation threatened Wazito shocked Ulinzi Stars 1-0 at Muhoroni Stadium in Kisumu.
Despite the win, Wazito remained 17th with 16 points, 10 points away from safety.