Gabriela Peñalba, a science teacher at West High School in Knoxville, reportedly had her back to the classroom when the teen snuck up behind her and ignited her hair and shirt with a lighter.
Exploiting the commotion, the student tossed the lighter out of a nearby window and fled, but was soon caught by school resource officers.
The unidentified suspect reportedly confessed to the crime in a police interview, but his motive remains unclear.
Luckily, Peñalba did not suffer serious burns — a result credited to the quick response of her students.
[photos via Facebook]