Pagham were forced to field a weakened side in their division-three west visit to Arundel because of injuries and illness.
Arundel were asked to bat first and thanks to a patient 47 from Will Clark and a hard-hitting 41 from M Barry, the home side managed to get to 140 for seven after their stipulated 53 overs.
Mark Ross (2-31), Wayne Green (2-39) and Sean Rutter (2-29) shared the wickets.
Pagham made a steady start and seemed to be cruising to victory at 94 for two, but the loss of skipper Stuart Rutter for 16 started a batting collapse which saw them all out for 128.
They were left believing a mixture of poor shots and equally-questionable umpiring conspired to see the quick fall of wickets.
Neil Chitty bowled his usual canny spin ending with five for 43.
Pagham need their batsmen to start supporting the bowling soon or they may be facing a hard season.