CC Madhya 18.187

‘advaita-brahma-vāda’ sei karila sthāpana
tāra śāstra-yuktye tāre prabhu kailā khaṇḍana
Word for word: 
advaita-brahma-vāda — the impersonal Brahman conception; sei — that saintly person; karila sthāpana — established; tāra śāstra-yuktye — on the logic of his scripture; tāre — unto him; prabhu — Śrī Caitanya Mahāprabhu; kailā — did; khaṇḍana — refutation.
Translation: 
When that person tried to establish the impersonal Brahman conception of the Absolute Truth on the basis of the Koran, Śrī Caitanya Mahāprabhu refuted his argument.