The Nigerian international impressed in his 37th La Liga game of the season to help Villarreal to a fine 4-0 win over Eibar at the Estadio de la Ceramica on Sunday.
Samuel Chukwueze was not on the scorer's sheet, but Andre Anguissa's fine finish, as well as three other second-half strikes, ensured that the Yellow Submarines would be in the group stages of the Europa League next term.
A cagey encounter ended goalless at halftime with Eibar having no relegation worries before kickoff.
But Villarreal needed an outright victory to guarantee a spot in Europe, and the hosts stepped up the energy after the break.
Their enterprising play yielded efforts minutes after Chukwueze made way for Ontiveros with Santi Cazorla supplying the assist for the opener.
The home side made sure of the points four minutes before time when Gerard Moreno's shot from the centre of the box found the top right corner following a fast Villarreal break.
Another Moreno goal and a late Moi Gomez strike minutes later sealed the win and confirmed the hosts' superiority in a largely one-sided game.
This dominating victory means no matter the result 7th-placed Getafe earn at Levante, they cannot overtake Villarreal, who sits in fifth place with 60 points.
