Krishna Das Kaviraja Maharaja explains in Chapter 2 of Caitanya-caritamrita Adi-lila that Lord Narayana possesses all six opulences in full – sad-aisvarya-purno.  He then distinguishes between Krishna and Narayana:

‘Narayana and Sri Krsna are the same Personality of Godhead, but although They are identical, Their bodily features are different’ [2.28]

‘This Personality of Godhead [Sri Krsna] has two hands and holds a flute, whereast the other [Narayana] has four hands, with conch, wheel, mace and lotus’ [2.29]

Kaviraja Maharaja then quotes Lord Brahma’s prayers to Lord Krishna from the 10th Canto of the Srimad Bhagavatam 10.14.14:

‘O Lord of Lords, You are the seer of all creation.  You are indeed everyone’s dearest life.  Are you not, therefore, my father, Narayana?  Narayana refers to one whose abode is in the water born from Nara [Garbhodakasayi Visnu], and that Narayana is Your plenary portion.  All Your plenary portions are transcendental.  They are absolute and are not creations of maya’ [2.30]

Kaviraja Maharaja gives three proofs that Krsna is the source of Narayana from Brahma’s prayers from 2.31 to 2.57.  He establishes that Narayana is the source of the purusa avataras.  The culmination of his reasoning is that Narayana is the vilasa or pastime feature of Lord Krsna [2.58].

He then quotes the maha-vakya verse of the Bhagavatam again.  The maha-vakya verse is the principle verse of a scripture or portion of a scripture.  This verse gives the predominant conclusion of the work.  Jiva Goswami calls this verse the paribhasa sutra or ‘the emperor verse’ of Srimad Bhagavatam.  There is no verse in Bhagavatam that contradicts this verse.  Krsna Das Kaviraja Goswami, therefore, completes his argument by quoting it:

ete camsa-kalah pumsah/krsnas tu bhagavan svayam/indrari vyakulam lokam/ mrdayanti yuge yuge

‘All these incarnations of Godhead are either plenary portions or parts of the plenary portions of the purusa-avataras.  But Krsna is the Supreme Personality of Godhead Himself.  In every age He protects the world through His different features when the world is disturbed by the enemies of Indra’ [CC 2.67 from SB 1.3.28]