Heard it in a football documentary. the documentary was about Jose Mourinho and how he's one of the greatest managers in European football history. The song is about becoming the greatest at something
A line they remembercan't break my focus to become the greatest
Could it be “The Greatest” by Sia? It has a female vocalist, and the song is about pushing yourself to become the greatest, so it sounds like a good match. I’m not completely sure without knowing which José Mourinho documentary it was, but it’s definitely worth checking.