Sure, Chiaotzu technically has two wins on his record, but let's be real—neither of them actually count.
First, there's Guldo. This fight happened in anime-only filler that isn't even canon to the actual Dragon Ball story. Plus, they were both already dead and fighting as spirits on King Kai's planet, so it's not like it was a real battle with actual stakes. You can't take credit for beating someone who's already been killed by Vegeta.
Then there's the Metalman. Chiaotzu defeated him by... calling him names. He literally made a robot cry by insulting it. That's not a fight—that's playground bullying. The Metalman was completely invulnerable to physical attacks anyway, so Chiaotzu didn't actually demonstrate any combat skill whatsoever. He just happened to have a sharper tongue than Tien.
So no, Chiaotzu still hasn't won a legitimate fight in Dragon Ball history. The little mime remains winless where it actually matters.