While some feel that Green Arrow is a lesser version of Batman, he saved the Justice League in a way that Batman never could. Despite the similarities, the Emerald Archer has a history and a legacy all his own, and nowhere is this better emphasized than with the first Green Arrow's son Connor Hawke. Connor was originally reluctant to take up his father's mantle, but when he did he would make his father proud by saving the entire Justice League using what everyone thought was Green Arrow's dumbest weapon of all time.
While Arrow decided to alter Connor's parentage, he was originally Ollie's son in the comics, and he first took over the Green Arrow persona after Oliver died deactivating a bomb in Green Arrow #101. Like many of DC's legacy heroes, Connor struggled at first to live up to his namesake, but eventually, he would gain more confidence in his skills and apply to join the Justice League in JLA #8. Unfortunately for him, Connor decided to join at the exact moment an obscure Supervillain simply named Key was attacking the Justice League Watchtower. With Earth's greatest heroes temporarily out of commission, only Connor was left to fight Key and save the League.
Key had managed to take over the tower using an army of robots and captured the league by trapping them in a hypnotic dream world, similar to the powers of the DC universe's most dangerous plant, Black Mercy. In order to defeat him, Connor needed to sneak around the watchtower and take out the robots one by one. But since he went to the watchtower expecting a simple job interview Connor didn't bring many weapons. Instead, he was forced to rely on Ollie's trick arrows that he found preserved at the JLA Watchtower. Among these weapons is the one arrow everyone loves to make fun of, the infamous boxing glove arrow.
While the rest of the League was helpless, Connor managed to pick apart Key's mechanical army using his father's old tools. At first Connor scoffed at the ridiculousness of a boomerang arrow and a boxing glove arrow, but these weapons proved to be more than capable of destroying Key's robots. Connor used the trick arrows to cut through Key's robots until he cornered the mastermind, ultimately defeating him with a single punch from his strongest weapon, the boxing glove arrow.
For a villain like Key who has ambitions for world domination, losing to an unknown hero like Connor and a boxing glove arrow was certainly embarrassing. And this is exactly why Connor wins. Even after he escapes Key's grasp, the villain underestimates Connor and doesn't consider him a threat. So when Connor finally gets the best of him in JLA#9 it is immensely satisfying to watch. Key prepared himself to fight Batman and Superman, but he had no idea how to fight Green Arrow's arsenal of tricks. Key's arrogance was his first major mistake, but it was the ingenuity and weapons of Green Arrow that ultimately defeated him and earned Connor Hawke membership in the Justice League in the process.