The Canada forward scored his first La Liga goal on Tuesday for Villarreal to open the scoring at Sevilla.
In the 16th minute, Oluwaseyi sprinted towards goal to poke home a cross from Sergi Cardona to make it 1-0 for the visitors.
The Yellow Submarine are coming off their first two defeats of the season, a 2-0 loss to Atletico and a 1-0 defeat by Tottenham Hotspur in the Champions League.
Background
Born in Nigeria and raised in Mississauga, Ont., Oluwaseyi joined Villarreal in late August on a five-year deal from Minnesota United.
A product of St. John's, the 25-year-old Oluwaseyi had 18 goals in 51 appearances across three seasons with the Loons.
Internationally, Oluwaseyi has scored two goals in 17 Canada appearances.