Bideford crashed to a 4-1 defeat at Street in Evo-Stik Division One South on Saturday in the first of three consecutive matches against the Somerset side.
The Robins conceded three times in the second half – twice in the final 10 minutes – as they suffered their first league defeat since September 1.
The visitors went behind to a strike from Ed Butcher inside five minutes, but a wonderful solo goal from Billy Tucker after half an hour hauled them level again.
The turning point came five minutes later when Ryan Turner was sent off after picking up a second booking, forcing Bideford to play an hour of the match with 10 men.
Philip Ormrod put Street ahead three minutes into the second half after following up a Ross McErlain header that hit the post.
As the game went into the final 10 minutes the hosts were able to extend their lead further. A Jamie Short shot deflected off Liam Gregory and went in to make it 3-1.
The Cobblers wrapped it up when Short found himself in behind the Bideford defence and got his effort on target in the bottom corner.
Bideford manager Sean Joyce was left less than happy with the decision to send Turner off.
“He was nowhere near the kid,” said Joyce.
“He’s gone to close him down and the kid has kicked his own shin. Turns was nowhere near him.
“He’s screamed as players in this league do and they’ve made a point of making the referee aware of it. It’s killed us.
“We stayed in it and had a go in the last five minutes and we got done on the counter attack. If it was 11 v 11 it would have been a better spectacle and a better game.
“Not for the first time this year we’ve been done by the referee.
“But we worked hard for an hour and didn’t chuck the towel in. Toby Down had a great game. He was immense.”
The two sides meet again on Saturday in the preliminary round of the Buildbase FA Trophy.
Bideford then go back to Street on Tuesday for a Southern League Challenge Cup tie.
“On Saturday we’re looking for an improvement and looking for a reaction,” said Joyce.
“Obviously we’ve had a look at them and we know what they’re all about now.”