John Gill Commentary 1 Kings 16:22

"But the people that followed Omri prevailed against the people that followed Tibni the son of Ginath: so Tibni died, and Omri reigned." — 1 Kings 16:22 (ASV)

But the people that followed Omri prevailed against the people
that followed Tibni the son of Ginath
Very probably they had a battle, in which the latter were worsted:

so Tibni died ;
in the battle:

and Omri reigned ;
took possession of the throne, his rival being slain.