In my West Marches game yesterday, the party was searching for a rumored dragon burial mound. They didn't find it, but they did stumble across a lake with an island housing a ruined monastery. And in that ruined monastery there was a fledgling bronze dragon atop the wall.
After much hemming and hawing about what to do (the dragon didn't talk, and seemed to be warning the party away), they scared it with some impressive phantasmal force spells (failed save and failed morale check!), then followed it into the ruins. It went into its nest to wake its brethren (as it was on watch). But a fireball wand and a magic missile spell finished them in the surprise round.
As the party were exploring the priory for loot, they heard a larger dragon roaring outside. Cue big battle!
Except I wasn't expecting it to be as epic as it turned out to be. The "adult" dragon (8HD 'small' bronze in my version of BECMI) had way less than average hit points, only 20 when the average is 36. It did have two more wyrmlings with it, though, so the battle could have gone south quickly. But the party had initiative in the crucial early rounds. The fireball wand took out the two wyrmlings, then the parent cast darkness while one of the party's magic users cast haste and another cast web on the entrance.
When the dragon came in, it got stuck for a few rounds in the web. It did manage to breathe on the cleric, but even though she failed her save, she had enough hit points to survive. The party managed to then inflict some serious damage on the dragon, but it then cast hold person on four of the PCs, and three failed their saves. It managed to get off both of its remaining breath weapons, but in its damaged state they didn't do much. The party finally finished it off.
And also, one PC has an arrow of teleportation. He drank a potion of luck to ensure that he'd hit with it and teleport the dragon away. It was a smart plan, but they managed to do so much damage to it that they called him off from using it.
It was a pretty tense battle, and I'm happy that it went on long enough to have the dragon cast a few spells and use all of its breath weapons (although I guess I should have had it use the fear gas breath after it was damaged, might have given it time to escape the web, but I didn't think of that in the moment, and the party was so spread out only one or two would have been gassed anyway).
I really enjoyed running the encounter, and I think the players had a good time as well. And now a few PCs get to level up!