Caitanya-caritāmṛta 5.6
sei kṛṣṇa — navadvīpe śrī-caitanya-candra sei balarāma — saṅge śrī-nityānanda
[sei krishna — navadveepe shree-chaitanya-chandra sei balaraama — sange shree-nityaananda]
Blended reading (Sanskrit + English inline)
sei kṛṣṇa — navadvīpe śrī-caitanya-candra sei balarāma — saṅge śrī-nityānanda
That original Lord Kṛṣṇa appeared in Navadvīpa as Lord Caitanya, and Balarāma appeared with Him as Lord Nityānanda.
My note
Source: vedabase.io