Nearly all top leadership positions were filled without contest, reflecting a strong show of unity and confidence among delegates drawn from across the country.
Oyuu was vying unopposed after the union successfully excluded Sossion and Omollo from the race.
In both KUPPET and KNUT, the contest for the influential Secretary-General position has been narrowed by eligibility rules, limiting who appears on the ballot.
The Kenya National Union of Teachers faces a standoff as it pushes ahead with elections despite court orders halting the process.
Oyuu said the process was already largely concluded, noting that the majority of candidates had secured their positions unopposed during nominations.
With the temporary injunction in place, union officials and members will have to wait until the court hears the matter on April 20.