The LaLiga side had managed to take command of the match thanks to two first-half goals from Karim Benzema and winger Marco Asensio.
12 minutes before the end of regular time Odriozola was able to add to the lead, and as the match drew to an end he was able to get an assist.
The right-back was played in from a short corner and managed to find himself free on the right edge of the box.
The ex-Athletic Bilbao man was able to find Cristo in the middle of the area, with the young substitute having an easy header to put his team 4-0 ahead and end any remainig hopes Melilla progressing in the competition.