During Maroon 5's show in Toronto Monday night ... the sound guys were having trouble and Levine was pissed ... so he chucked the mic in frustration, which took a crazy bounce and nailed a female fan in the face.
Levine immediately ran over to check on Stephanie Green in her front row seat -- she was fine, and about to get better. Watch the vid ... Adam got pretty smooth, and most likely dodged a lawsuit in the process.
Must've learned that move from Jagger. There, we said it.