Thembi Kgatlana bagged the only goal for Eibar but her side surrendered a one-goal lead to lose 2-1 at Rasheedat Ajibade and Ajara Nchout's Atletico Madrid in Sunday's Primera Iberdrola fixture.
Following a 2-2 draw with Real Sociedad in last time out, Iker Dorronsoro's ladies were aiming for a return to winning ways but ended up crumbling to a seventh defeat of the season in Madrid.
With a huge ambition to upset the former champions, the top-flight newcomers handed the South African star her ninth league start of the season, along with her compatriot Noko Matlou.