Legal Question in Landlord & Tenant Law in California

You would have to look at the specific language of your local rent control ordinance, but I suspect it will not check my opinion. You ended the lease, not the landlord. No notice had to be given to you as you were the one who said you would leave and your landlord relied upon that in renting it out to another person. The landlord would be liable to that other person if he let you stay. The landlord should be able to win the unlawful detainer suit against you and you will be liable for a reasonable period of time after you leave for the rent until he can find a new tenant or sooner [courts usually use thirty days as standard for landlord to find a new tenant]. It was not your landlord's fault that the problem arose, so why should he have to pay for it?

Mr. Shers is right. No rent control ordinance allows a tenant to give notice, make the landlord find a new tenant, and then change their mind. You are unlawfully holding the premises. That is what unlawful detainer means. He will win. Your remedy is with the new landlord who cancelled your move into the new place.