"I had a Diamond League to try and win, and I managed to do that so it's a pretty good feeling, that's for sure.
"[I'm] on top of the world, I've just extended that PB and the New Zealand record by a few, so it's a great feeling and it's awesome to finish off the season well because it's sometimes hard to find motivation, but I definitely had a bit of it after third place in Rio.
"It's awesome. It's going to be a hell of a next four years with the world champs in the next couple of seasons, and there's quite a few young guys on the scene now with Ryan [Crouser] and Joe [Kovacs] and a few other Americans, so it's going to be pretty tough, but it's going to be pretty fun as well."
Walsh finishes the overall season 16 points clear of American Joe Kovacs and nets US$40,000 ($55,000) for winning the trophy.
He joins Valerie Adams as the only New Zealanders to win Diamond League crowns.
Adams won four times from 2011-14, and is set to win a fifth at Brussels next week.