Cristiane Justino Santos, 26, the Strikeforce women’s featherweight champion and considered by many as the baddest woman on the planet, tested positive for anabolic steroids the day before her most devastating career win.

According to a release by the California State Athletic Commission, the featherweight champion, better known as “Cyborg,” tested positive for the anabolic steroid Stanozolol, also known as Winstrol.

The test took place on Dec. 16, the day before she knocked out the top contender for the title, Japan’s Hiroko Yamanaka, in just 16 seconds.