The former Bradford and Walsall keeper also had to dive low to get a hand to substitute Edgar Benitez's goalbound drive and also push away a header from Cristian Riveros.
Vokes replaced Wolverhampton Wanderers team-mate Edwards and he wasted little time in showing his potential threat as Agaev needed to be at his best to push Vokes' looping header over.
Rangers should have taken the lead after 23 minutes, a Mikel Arteta free kick finding Paolo Vanoli only for Timo Hildebrand to push away the diving header from 14 yards.