Berwick Bandits overcame the loss of skipper Matthew Wethers in a horrific crash to beat the Premier League leaders on a thrilling night in front of the Sky Sports cameras.
Wethers was taken to hospital after being catapulted over the fence in a heat 14 collision with Edinburgh Monarchs rider Aaron Fox.
But after a long delay while both riders received medical attention, the Bandits held their nerve in the final-heat decider, winning it 5-1 to record a stunning victory.
Czech rider Matej Kus, starting at reserve, was the star man for the home side, winning his first four races and finishing with an impressive points tally of 16+1.
Fourth in the table, the Bandits went into the meeting full of confidence following wins over Redcar Bears and Sheffield Tigers last week, and this superb victory over the Monarchs should be enough to secure a top-six spot and seal their play-off berth.
On a night of drama, thrills and spills, Berwick built up an 18-point lead after surging to successive 5-1 wins in heats 8, 9 and 10. But they almost threw it away as the Monarchs came roaring back.
The visitors narrowed the gap to eight points after a 5-1 win of their own in heat 13, and a dramatic penultimate race took the meeting right down to the wire.
When Bandits rider Alex Edberg lost control on the first bend and was disqualified, heat 14 had to be re-run without him.
The Bandits still had an eight-point lead, but it was soon cut to three points after the ensuing crash in the three-man re-run.
Wethers and Fox were going hammer and tongs until they collided at full speed on the final bend of the last lap. The coming together sent Wethers spinning off his bike and into the air over the safety fence.
As race medics immediately rushed to the aid of both riders it was clear that the crash was a serious one.
Fox received treatment on the track while paramedics attended to Wethers in an awkward position just over the fence.
After a long delay, both were removed from the track before the county ambulance was called.
Using the benefit of replays on the Sky Sports cameras, the referee decided Wethers had caused the crash and disqualified him from the heat.
With Edberg already out, that meant the Monarchs were handed a 5-0 win and put them in with a chance of snatching victory in the final heat.
Leading 43-40 going into the decisive final heat, the Bandits suddenly faced the prospect of snatching defeat from the jaws of victory.
But French rider David Bellego kept his cool under pressure on the final heat. Grabbing the lead with a courageous pass, he held on the claim victory ahead of team-mate Kus to wrap up a decisive 5-1 win for the Bandits as the crowd roared their approval.
BERWICK BANDITS 48
1. Claus Vissing R,2*,2*,1 = 5+2
2. David Bellego 1,3,2*,3,3 = 12+1
3. Steen Jensen 1,0,N,0 = 1
4. Matthew Wethers © 0,3,2*,Fx = 5+1
5. Kevin Doolan 2*,3,1,0 = 6+1
6. Alex Edberg ® 2*,1,R,Fx = 3+1
7. Matej Kus ® 3,3,3,3,2,2* = 16+1
EDINBURGH MONARCHS 41
1. Craig Cook 3,1*,2*,3,1 = 10+2
2. Justin Sedgmen 2*,2,1,3,0 = 8+1
3. Max Fricke 2*,Fx,0,3 = 5+1
4. Steve Worrall 3,2,1^,2* = 8+1
5. Sam Masters 1,1,1^,2* = 5+1
6. Aaron Fox ® 0,0,0,1,3 = 4
7. Derek Sneddon © ® 1,0,F,N = 1