CC Madhya 9.138

pūrve bhaṭṭera mane eka chila abhimāna
‘śrī-nārāyaṇa’ hayena svayaṁ-bhagavān
Word for word: 
pūrve — before this; bhaṭṭera — of Veṅkaṭa Bhaṭṭa; mane — in the mind; eka — one; chila — there was; abhimāna — an impression; śrī-nārāyaṇa — the form of the Lord as Nārāyaṇa; hayena — is; svayam — personally; bhagavān — the Supreme Personality of Godhead.
Translation: 
Before this explanation was given by Śrī Caitanya Mahāprabhu, Veṅkaṭa Bhaṭṭa thought that Śrī Nārāyaṇa was the Supreme Personality of Godhead.