IPFW claimed its second consecutive victory over a top-ranked opponent on Thursday with a 3-2 victory over No. 15 George Mason in Long Beach, Calif.
The Mastodons (9-7) had won two of the first three sets, lost the fourth, then won the fifth 15-9 to defeat the Patriots (9-9).
Last week IPFW defeated No. 10 Penn State.
After losing the first set 25-15, IPFW won the next two by identical 25-22 scores, then lost the fourth, 25-21.
Eddie Rivera, Andy Sellan and Anthony Randolph had 13 kills each for the Mastodons, who face No. 3 Long Beach State on Saturday.