While many lease terms are geared towards protecting landlords, of course, leases contain items that create responsibilities for landlords. Failure to meet your obligation under the lease could be used as an eviction defence.
For example, leases typically state that landlords are required to provide a safe environment and make repairs when notified by the tenant. If a tenant gave you proper notice regarding a needed repair, you failed to make said repair and then the tenant withheld rent (for which you’re now trying to evict them), they tenant may have a solid defence that could defeat your eviction.
Before you commence an eviction proceeding, make sure you’ve not violated any terms of the lease that could come back to bite you. Also, if you are trying to evict a tenant for violating a lease term that you added after the original lease agreement was signed and did not get the consent of the tenant, such as raising the rent or requiring them to perform certain maintenance, a court is likely to deny your eviction request.