Śrīmad Bhāgavatam 12.2.29-30

viṣṇor bhagavato bhānuḥ

kṛṣṇākhyo 'sau divaḿ gataḥ

tadāviśat kalir lokaḿ

pāpe yad ramate janaḥ

(Śrīmad Bhāgavatam 12.2.29-30)

The Supreme Lord, Viṣṇu, is brilliant like the sun and is known as Kṛṣṇa. When He returned to the spiritual sky, Kali entered this world, and people then began to take pleasure in sinful activities. As long us Lord Śrī Kṛṣṇa, the husband of the goddess of fortune, touched the earth with His lotus feet, Kali was powerless to subdue this planet. Although even during the time of Lord Kṛṣṇa's presence on earth Kali had entered the earth to a slight extent through the impious activities of Duryodhana and his allies, Lord Kṛṣṇa consistently suppressed Kali's influence. Kali could not flourish until Lord Kṛṣṇa had left the earth.