Perfectly Timed Invader Kill (Destiny)
I know everyone loves to hate on Gambit, but it's moments like this that keep me coming back. Playing with randos, the first invade from the enemy team was damaging (nobody really fought back).
I got a chance to invade on the second go-round, first guy I found had just deposited (bad), but I caught him JUST as he was entering the portal. He died, the portal considered itself activated, they lost their invade.