Triumphal entrance refers to the triumphal entry of our Savior into the third heaven, which is beyond the stellar universe. His procession from earth in bodily form was the first entry by any human being into Heaven. He is the first-fruits of our salvation.
His glorified humanity sits at the Father’s right hand on the Throne of Eternity. All believers who have died physically are in the Third Heaven with our Savior, which is why He died in our place, so we could be with Him in His place (John 14:2).
I, personally, would like to have seen that for myself. What a Homecoming that must have been.