Central midfielder Keith Imbali netted the match winning goal for Sharks in the 66th minute.
Nzoia Sugar have been dealt a blow in their hope to land the Kenyan Premier League title after losing 1-0 to Kariobangi Sharks at Sudi Stadium.
This is the first defeat the Bungoma based club has suffered while playing in front of home fans.
Nzoia were in dire need of the three points heading into the clash so as to move to a point within the reach of league leaders Tusker.
However, the Salim Babu coached side could not capitalize on home advantage and put Sharks to the sword and extend their fine home run.
Central midfielder Keith Imbali netted the match winning goal for Sharks in the 66th minute.
The defeat means that the best Nzoia can do is to hope that Tusker and the second-placed Gor Mahia will share spoils when they meet on Sunday.
Elsewhere, Mathare suffered their tenth straight win after losing 1-0 to KCB at Ruaraka grounds.
Musa Masika scored the sole goal in the second half to send Mathare close to the exit door.
With three matches remaining, Mathare will be forced to win all of them and hope that Wazito will falter so as to secure the playoff slot.
Meanwhile, Sofapaka came from a goal down to edge Posta Rangers 2-1 at Kasarani Annex.
Rangers had taken the lead through Michael Apudo but second half goals from Stephen Okola and Rody Manga were enough to deliver the three points to the former champions.