The National League division two south match, which was supposed to be a home fixture, was hosted at St Peter’s School in Exeter.
Portsmouth will now have to make another long journey to Devon for the return leg.
Player-coach Nasser Ssemuwemba said: ‘We failed to secure a sports hall on time and we could not agree on alternative dates for the match.
‘Exeter kindly proposed to host the match as long as we shared the costs.
‘So, after consultations with Volleyball England, we all agreed to travel to Exeter.
‘It was the only viable option left to stop us from a match forfeiture, which could have been more detrimental to our chances of avoiding the drop.’
Despite an arduous journey, it was Portsmouth who looked lively in the early exchanges of the opening set with opposite player Joan Francesc Cabrer Gomila linking up well with setter Matthew Jackson.
But they later lost concentration as refereeing calls went against them, allowing Exeter to storm away and win 25-17.
Exeter then doubled their advantage 25-18 with well-placed serves and clinical attacks.
Although universal player Adamantios Xanthoudidis tried to rally his troops in the third set, poor decision making allowed Exeter to seal the victory 25-19.
But Xanthoudidis reckons Exeter were there for the taking.
The Greek player said: ‘I know we did not have our best team out there and only had six players but we took the fight to them in the first part of the opening set and they looked vulnerable.
‘But people became quiet on court and it was left to me to keep trying to talk and boost morale.
‘Even with out our best team, we need to show some steel and try to motivate ourselves by celebrating each point won together.
‘It’s going to be that season where we have to fight for each point in order to keep ourselves afloat.’
Egyptian attacker Akram Mahmoud Samir El Saka won his second man-of-the-match accolade, while there was also an impressive debut for new signing Louis Bachu.
Portsmouth, who have won once this season, visit Tendring VC Men II on Saturday, December 10 in Essex (4pm).