Barnstaple Town suffered a heavy defeat to Division One South play-off hopefuls Slimbridge on Saturday.
Barum were beaten 4-0 in Gloucestershire, with all of the goals going in during a nightmare 20-minute period in the first half.
Soloman Wanjau-Smith, who scored two goals for Slimbridge in a 3-0 win in the reverse fixture, was on target again this time out, netting twice from the penalty spot.
The first spot-kick was given after 16 minutes when Oliver was deemed to have brought down Adam Price as he rounded the Barnstaple keeper.
Wanjau-Smith converted and did the same four minutes later after he was felled by Brian Levien.
The third goal came after 33 minutes when Rhys Sarson put a low shot past Oliver.
Sarson claimed his second and Slimbridge's fourth three minutes later, following up on an Aaron Nesbeth shot saved by Oliver.
Barum had to play the final 15 minutes with 10 men after Mike Humphreys was sent off for picking up a second yellow card.
Manager Dean Edwards said: "I am in no doubt that side will make the play-offs. They've been together a while, they're young, fit and strong and they're by far and away the best side we have played this season.
"We haven't been battered like that since Thatcham away - the game was over after 30 minutes and it was about damage limitation come half time.
"We got wiped out in the first half, but in the second we could have scored a couple and started to look a bit better but it was too late by then."
Despite the result, Barnstaple Town are off the bottom of the table.
Basingstoke Town have been deducted a point by the Southern League for fielding a suspended player in a 0-0 draw against AFC Totton in September.
The adjustment means Basingstoke (14 points) replace Barum (15pts) at the foot of the table.
Barum have a crucial away match this Saturday against Moneyfields.
Moneys sit 18th in Division One South, three points ahead of Barum.
While Barnstaple will be without Humphreys, they will get Kai Fisher back from suspension.