Eva Csernoviczki was trying to resist a strangle in her 48kg quarter-final against Belgium's Charline van Snick when she passed out, collapsing to the mat.
The referee immediately stopped the bout, awarding it to Van Snick, while Csernoviczki's arm started shaking before she regained consciousness.
A medic was called but the Hungarian quickly recovered and was able to leave the mat without assistance.