COTU boss Francis Atwoli, who is one of the most vocal proponents of Azimio presidential candidate Raila Odinga, appeared to have convinced voters in his backyard to back the ticket.
Raila garnered 27,997 votes in Khwisero constituency, Kakamega County, where the trade unionist comes from.
Deputy President William Ruto of the United Democratic Alliance (UDA) garnered 5,201 votes in the same constituency.
Kakamega neighbours Vihiga, the home county of ANC party leader Musalia Mudavadi - who is also Atwoli's nemesis.
The Cotu boss delivered 83.6 per cent to Azimio compared to Mudavadi who delivered 76.8 per cent in his polling station, Mululu Primary School. Results of the ANC boss' constituency, Sabatia, are yet to be released.
Azimio dominated in Kakamega County, based on provisional results on the IEBC portal, although official results are yet to be declared.
The two leaders have been vocal in the Western region during the campaign season for their preferred presidential candidate.
Atwoli ridiculed the former Vice President's power deal with Ruto - where he was to get a 30 per cent power sharing deal but on condition that he delivered 70 per cent of the votes in Western region.
In an earlier statement when ANC joined hands with UDA, Mudavadi took a jab at the COTU boss who has held the position since 2001. He stated that he will incorporate drastic changes in trade union body to benefit the laborers.
"COTU will not be a clownish cowboy club that labours for a few individuals. Under my watch, the labour movement is going to regain its sense of purpose and respectability as the middle employers and their employees," the former Vice President vowed.
Atwoli also accused Mudavadi of being a sell-out in the Luhya community. He added that the party leader's decision decision to support the Deputy President would not result in him being president.
"He has lied to Kalonzo and Gideon by hiding his marriage with Ruto," the self-confessed Luhya elder stated.
