Well, that's not a surprise considering that normal and fighting type moves have no effect on ghost Pokemon. A Hitmonlee is pretty much doomed against a level 1 Gastly.
The real question is, assuming that a trollback is ever imminent (and it is), which is less risky? Trying to carefully damage the target Pokemon with weaker, predictable moves and then throwing Pokeballs, or just going in with Pokeballs blazing? Since I've caught a lot of Pokes in 1-2 tries while they were still 100% healthy, and thus it seems that the chances of doing so aren't all that low, I'm leaning towards the latter... It's time, not Pokeballs, which you really have to be stingy with.
hat's why I'm always carrying a low level Poke when I'm hunting. So if I encounter with the desired Poke I can lower its HP without risking of KOing it.