When a young woman refugee in Casablanca asks Rick if Captain Renault's word can be trusted (Renault offered to help her and her husband out with the finances but only if she'd had one night stand with him). But she unintentionally goes on and on about her love for her husband, convincing Rick to step in and get his roulette croupier to rig the game for one win and enough money for the couple to buy their way to safety in America.
And when Rick's staff (made up of exiles and refugees like himself) find out, the Russian bartender even hugs and kisses him for his humane act.
While not as iconic as Rick's sacrifice mentioned above, Viktor gets a similar one just a few scenes earlier when he tells Rick to get Ilsa out of Casablanca and keep her safe, even at the cost of losing his own opportunity to leave. "Apparently you think of me only as the leader of a cause. Well, I'm also a human being. Yes, I love her that much."