This is why I tend to keep junk rods kicking around as well to help burnish the threads by stretching/torquing a few times. I've had this issue before as well and now just keep a nice "new" wrench with a welded extension handle on the open end of it for leverage. Good for rod nuts/bolts because it hasn't been worn down from years of use in other avenues
Sounds like you're all good to go now though