There's a famous story about this when Rishis were performing yagam for welfare of the people in Kaliyuga, Maharishi Bhirgu hit Lord Vishnu's chest on seeing who's the supreme. Upon hitting Vishnu's chest, MahaLakshmi got angry with the Lord and went out of Vaikuntha and descended to Earth as Padmavathy.
Now my question is, in which Kalpa/Manvantara/Mahayuga it happened? Which Purana has reference to this story?