Players like Libor Sionko, Filip Sebo and Karl Svensson added some experience to the Gers side against a strong Kilmarnock team but the visitors were to take all 3 points after a excellent second-half display.
The Game Ramained Goaless at half time but their were concerns for the coaching staff when Adda Djeziri had to be replaced after 31 minutes with a collar bone injury which could rule himself out of the under-19s crunch league decider against hibs on friday.
Killie however stepped up a gear after the interval and the electric Aime Koudou opened the scoring on 51 minutes when he finished confidently at the back post after Willie Gibson had provided a teasing cross.
The Ivory Coast Striker was looking to impress Jim Jefferies in the stands and the Rugby Park boss would have been happy to see the former Airdrie Utd player score on 68th minutes with a overhead kick.
Midfielder Tommy Nolan increased his side's advantage on 73 minutes with a curling volley after a mistake by Ger's keeper Joe Sugar, Killie substitute Scott Anson added the fourth with a tap in on 84 minutes.
Rangers: Sugar, Svensson,(park) N.Gallacher, Donald, Sionko, McShea, Van Der Broeck, Djeziri, (Campbell) Sebo, (K.Hutton) Little
Kilmarnock: Harpur, Clancy, O'Leary, Iain Campbell, Noble, Nolan, Gibson, Flannigan, Dodds, Skora, Koudou