Deputy President William Ruto's strongman and key ally Kimani Ngunjiri has lost his Bahati parliamentary seat.
The outspoken MP, who ran under the United Democratic Alliance, was defeated by Jubilee's Ms Irene Njoki, an ex-aide of Roads and Transport Cabinet Secretary Macharia Kamau.
Bahati Returning Officer George Karani announced Ms Njoki, a first-timer, won with 34308 votes against her closest competitor, Mr Ngunjiri, who received 26,809.
Ms Njoki has joined other women in the county who have held top elective seats.
In the previous Parliament, Nakuru had five elected women.
They included outgoing MPs Martha Wangari (Gilgil), Charity Kathambi (Njoro), Jayne Kihara (Naivasha), Liza Chelule (woman representative) and Senator Susan Kihika.
Ms Njoki ran against Mr Ngunjiri and four others – Nakuru businessman John Mbugua, Mr Quindos Karanja, Mr Paul Mwaura and Mr Steve Kihara.
During her campaigns, Ms Njoki touted her planned empowerment programmes for youth and women in the constituency.
Speaking after she was announced winner, she said she was ready to serve Bahati voters.
"I want to bring the much-needed change that is long overdue. I want to create a positive change in education, youth and women empowerment, water access, roads, among others,” she said.
Ms Njoki, an experienced civil servant, was born in Bahati constituency, Nakuru County, in December 1975.
She holds a master’s degree in strategic management from Daystar University and a bachelor’s in marketing from Africa Nazarene University.
She worked as a personal assistant to the marketing manager at the New Stanley Hotel before moving to Kensta Group, where she was an assistant to the managing director.
In 2005, she worked at NCBA Bank as the executive personal assistant to the managing director.
After working in the private sector for 15 years, she joined the government in 2013 as personal assistant to the Cabinet Secretary for Health.
Before she joined elective politics, she was an aide to the Roads and Transport CS, Mr Kamau.
She ran a well-oiled campaign, making inroads in the constituency that Mr Ngunjiri has held for two terms.