It was shown in the movie Bajrangbali - one ruler (I forget his name) who had taken shelter with Anjani, who in turn asked Hanuman to protect him, and after Hanuman committed to it, he found out that he was to protect him from Rama!
The way it happened is that Hanuman built a fort/wall around him, and had Rama's name written all over it. Reason Rama was after that ruler was that Vishwamitra was pissed at him and asked Rama to kill him or produce him at his feet, and reason Vishwamitra was pissed at him was that he had omitted to honor him, and the reason he had omitted to honor him was at Narad's behest. So this whole drama took place, and when Rama couldn't kill the ruler, the ruler surrendered to him, and Rama got to deliver him at Vishwamitra's feet, thereby keeping his end of the deal, while Hanuman too had successfully protected him, thereby keeping his. End result: everybody happy.
Sorry if I seem a little rushed in describing this story. This story seems to be a treta yuga instantiation of Krishna's Tulabharam incident, where the moral is that the name of the god is greater than the god himself.
If you go to dailymotion.com and search Bajrangbali, it's the last but 1 episode i.e. 12 or 13.