SB 1.3 - Kṛṣṇa's independent form
One should not state a predicate before its subject. Thus kṛṣṇas tu bhagavān means that Kṛṣṇa (the subject) fulfills completely the qualities inherent in Bhagavān, the predicate. It does not mean that Kṛṣṇa is another form of Bhagavān. Thus it means Kṛṣṇa alone is Bhagavān, the basis of every other form. This is made clear by the word svayam. This means Kṛṣṇa is superior to the puruṣāvatāras called Bhagavān and even to Mahā-Nārāyaṇa.
SB 10.1.23 says that sākṣād-bhagavān Kṛṣṇa, who has full potency (puruṣaḥ paraḥ), will appear in the house of Vasudeva. Brahmā speaks these words (vasudeva-gṛhe sākṣād bhagavān puruṣaḥ paraḥ), originally spoken by Kṣīrodakaśāyī Viṣṇu to him, to the demigods. So Kṛṣṇa is not Kṣīrodakaśāyī. He is not Garbhodakaśāyī because He is called para-puruṣa, the supreme puruṣa, whereas Garbhodakaśāyī is the second form of the puruṣa. Is Kṛṣṇa then Mahā-Viṣṇu, the first puruṣa? No, because He is called bhagavān. Is He then the Lord of the spiritual sky, Nārāyaṇa? No, because He is called sākṣāt-bhagavān, the form of Bhagavān who is not dependent on any other person.