Keroche Breweries boss Tabitha Karanja is the new Nakuru County senator.
Ms Karanja was announced the winner after trouncing her nine competitors in the crowded race.
Vying on a United Democratic Alliance (UDA) party ticket, Ms Karanja secured 442,864 votes against Mr Lawrence Karanja of Jubilee Party who trailed at 163,685.
Other candidates: John Mututho of ODM got 36,472votes, Daniel Kimani Gitau (Ford Kenya) 5,975, independent candidates Boniface Gacinga 7,223, Dorothy Macharia 10,745 votes and Koigi Wamwere 6,335 votes.
Ms Karanja won the seat in her first attempt after joining politics last year. She will take over from Ms Susan Kihika who successfully vied for governor's seat.
In her acceptance speech, Ms Karanja thanked the party and Nakuru residents for entrusting her with the position and promised not to let them down.
Ms Karanja argued that the residents of Nakuru have shown their confidence in the ability of women and vowed to prove that women can perform better when given the opportunity.
"I know there are those who are skeptical about the women leadership but I am here to prove that we are equal to the task. I will transfer the experience I gained in the corporate world to public leadership and I will be there to hold to account the county administration, " said Ms Karanja.
Ms Karanja who is the founder and CEO of Keroche Breweries Limited.
A voter Mr Dan Mahiri had petitioned the court for orders declaring Ms Karanja unfit to hold public office over her run-ins with government over tax evasion claims.
The matter is still pending in court.