William Jebor scored the only goal of the game as Liberia beat Zimbabwe 1-0 in Sunday's Africa Cup of Nations qualifier in Monrovia.
Defeat means the Warriors miss the opportunity to secure their AFCON ticket with a game to spare, and instead, they must avoid defeat against Congo-Brazzaville in March to secure their berth in Cameroon next year.
Despite the loss, Zimbabwe remain atop Group G with eight points, while Liberia move up to second on seven points.
In Brazzaville, the Republic of Congo drew 1-1 with the Democratic Republic of Congo to leave both teams in with a chance of reaching the AFCON.
The Red Devils are bottom of the pool, on five points, heading into the deciding round next year, while the Leopards are one point ahead of them in third.
The DRC host Liberia in March, while Congo are away in Zimbabwe.
Sunday's defeat represents a setback for a Zimbabwean side who took four points from the DRC during October's double-header.
They largely controlled the contest but were unable to take their chances, with Tinotenda Kadewere particularly culpable, before Jebor's 72nd-minute winner secured all three points for the hosts.