[Haskell-beginners] combine pattern matching against named fields and tuples

I'm trying to do something like this: data Thing = Thing { field1, field2 :: ( Int, Int ) } myfunc = Thing { field1 ( _, x ) } = x but it doesn't work. That is, I want to match against the second item of the tuple which is the named field1. I'm not just trying to do this particular thing, but trying to figure out if some kind of general pattern matching can be done like this.