This Marine scared off a Japanese cruiser with a mortar
Leland "Lou" Diamond joined the Marines in 1917, and by the time World War II came around he'd become an expert mortarman.
He was so good, in fact, that the hard-charging Leatherneck took on a Japanese cruiser at Guadalcanal by himself and forced it to withdraw.
After joining the Corps during World War I, Diamond quickly made a name for himself as a Marine's Marine. He was known for walking around without his cover, wearing his dungarees most of the time and for having a loud and dirty mouth.
You can read more about Leland "Lou" Diamond and his skill with the mortar here.