Bahati UDA Parliamentary candidate Kimani Ngunjiri has lost his seat to Jubilee counterpart Mrembo Irene Njoki.
The outgoing MP lost with more than 7000 votes which is so far the biggest winning gap among MPs in the region.
The MP-elect, a public service career woman who resigned from the Ministry of Transport and Infrastructure, got 34,308 votes against Ngunjiri's 26,809 votes.
Ngunjiri was seeking a third tenure in office after clinching the seat in 2013.
He first won on a TNA party ticket in 2013 and through Jubilee in 2017.
His first win came after he encountered many losses since the late 1980s when he was a Kanu stalwart.
Ngunjiri defected to UDA and has been strongly supporting Deputy President William Ruto.
The abrasive legislator is famous for his Facebook posts where he often times attacks President Uhuru Kenyatta and his rivals.
Speaking after receiving her certificate from the area Independent Electoral and Boundaries Commission (IEBC) Retuning Officer, George Karani, Njoki said Bahati needed a change in leadership.
She thanked the electorate for choosing her to represent them and promised to serve them diligently.
"My team has worked tirelessly and I pledge to diligently serve the people of Bahati because that's what leaders are chosen to do," she added.
Njoki has been working with different communities on various projects including water supply, electricity connections, market upgrades and road construction.
The philanthropist has also been sponsoring children through education while at the same time imparting skills to youths through competency courses.
In her acceptance speech, Njoki said she would seek development funds for Bahati beyond the National Government Constituency Development Fund (NGCDF).
"I pledge to use my office to create partnerships with development agencies and donors to seek funds for different projects," she said.
Njoki observed that while NGCDF was a great way of improving livelihoods at the grassroots, leaders could use their networks to get further funding.
Meanwhile, Nakuru East MP, David Gikaria has retained his seat.
The United Democratic Alliance party candidate garnered 30,810 votes against his closest contender, Jubilee's Joel Kairu who managed 25,965 votes.
Gikaria has had several conflicts with the law the latest one being on election day.
The former civic leader at the defunct Nakuru Municipality will be serving his third term as the area MP.
Gikaria served as a councillor for ten years and was at one point elected the Nakuru Municipality mayor.