OP, I was in your shoes, a year ago. Took the interview, got the job and quit the job I started 3 weeks earlier to take the one I really wanted.
Unfortunately for me though, the job I *really* wanted turned out to be a nightmare. I quit 4 months in.
The Gods smiled at me and I bounced back but if I had to do it over, I would have just stayed put at my original job instead of thinking the grass is greener.
Good luck to you.