Barcelona's Liga Iberdrola title dreams were ended after they were defeated 1-0 by Tenerife at the Estadio La Palmera on Sunday.
After a scoreless first half, Cameroon international Raissa Feudjio teed up Maria Jose to score in the 56th minute for what turned out to be the match-winner.
With Barcelona's defeat, Esther Gonzalez's hat-trick ensured Atletico claimed a 3-1 win at Estadio Zubieta XXI and emerged champions for the third sucessive season.
Cameroon's Feudjio, who last the duration of the game, made nine appearances since joining Pier's side in January.
While Cote d'Ivoire's Ange N'Guessan, who was taken off in the 82nd minute, was making her 30th outing and scored four times for Tenerife.
Nigeria's Oshoala, who played the whole match, made her fifth start in seven league appearances and scored seven goals for Barcelona.
The win means Tenerife ended the season in fourth with 54 points, while Barcelona finished second with 78 points - six behind Liga Iberdrola champions Atletico.