During the Princes of Darkness arc, Stargirl and Billy Batson find the dying body of Alan Scott. They encounter the Shade, who is somewhat reluctant to help. Stargirl (a teenage girl with no powers outside of an energy belt and energy staff) browbeats the Shade (one of the most powerful and longest-lasting DC villains) into helping them out. He's clearly impressed.
In the same arc, Alan Scott returning to the Green Lantern name and ending the shadow threat, saving his son in the process.
The second Hourman sacrifices himself in the place of the first (while the third, his son, tries to make his own sacrifice).
Nathan Heywood's second issue, in which he gains his superpowers by saving his few remaining relatives from a metal villain by stabbing him in the throat. With a broken crutch. Mid-gloat.