Uche started the game for the Yellow Submarine and was paired upfront with Giovanni dos Santos but Dos Santos had to be replaced in the 48th minute by Jonathan Pereira.
The goal came after Jonathan Pereira miscued a cross from the left flank by Hernán Pérez but Uche was at the right spot at the right time to lift the ball over the Elche goalkeeper, Manu Herrera for the only goal of the encounter.
The Nigerian striker, not on the 25-man list released by Stephen keshi had teed up Mario in the 53rd' minute but the shot was saved by Herrera.
Uche had 81% pass accuracy from 61 touches on the ball and managed two shots on target from which he scored one. His total is now three goals in nine league appearances as Villarreal stay fourth on the La Liga table.