How did Lord Vishnu get Sudarshana Chakra?

Depicting about Sri Ram's manifestation Mahadeva told Parvati–'Once, Swayambhuva Manu had communicated his craving of having Lord Vishnu as his child to which Maha Vishnu (Sub of Garbhodakaśāyī Vishnu and Ksirodakaśāyī Vishnu {Paramātmā}) had concurred.

Proceeding with the story of Sri Ram, Shiv advised devi – Dasharath mentioned Vashishth to play out the Jaatkarm Sanskar of Sri Ram. In course of time Kaikeyi brought forth Bharat–a manifestation of Panchajanya conch. Also, Sumitra brought forth two children Laxman and Shatrughan. Laxman was the manifestation of Sheshnag while Shatrughan was the manifestation of Sudarshan Chakra.