A composition comprising an ethylene-based polymer is made by a process comprising the steps of: (A) contacting under first polymerization conditions at least ethylene and at least one molecular catalyst to form a first ethylene-based polymer, and (B) contacting under second polymerization conditions the first ethylene-based polymer of (A) with at least additional ethylene and a carbon-carbon free radical initiator of Structure (I): wherein R1, R2, R3, R4, R5 and R6 are each, independently, hydrogen or a hydrocarbyl group and wherein, optionally, two or more R groups (R1, R2, R3, R4, R5 and R6) form a ring structure, with the proviso that at least one of R2 and R5, and at least one of R3 and R6 is a hydrocarbyl group of at least two carbon atoms, to form the composition.