Rangers edged out Legia Warsaw 1-0 at Ibrox thanks to a stoppage-time goal from Alfredo Morelos following a 0-0 draw in Poland last week.
Earlier in the evening, Celtic dismissed AIK Stockholm 4-1 in Sweden (6-1 aggregate) to book their place in Friday's 12 noon draw.
James Forrest, Mikey Johnston, Christopher Jullien and Lewis Morgan were all on target for Neil Lennon's team.