Zakaria Sawo decided just over a minute before full time with an exquisite brass kick from ten meters away.
Lucas Larade sent Jerv into the lead at Sør Arena after 56 minutes, when he poked the ball into the net from seven meters after a corner.
The Frenchman went straight into the team after being out of the squad for the last three weeks due to a thigh injury.
Here Larade was tame in the duel game.
Øystein Øvretveit stopped Sanyang at full fours in the back room before the break.
In overtime of the 1st half, André Richstad should have sent Jerv to the dressing room with the lead, but instead he blew the ball over the goal.
Just five minutes after Jerv’s goal, Mathias Grundetjern thought he had equalized with a brilliant solo raid.
Sanyang, on the other hand, was offside and disturbed Jerv goalkeeper Øystein Øvretveit, and the goal was cancelled.
Seconds later, the ball was in the Start net, but again it was offside, now by substitute Cijntje
Start, which has been in crisis on and off the field in recent weeks, passed with the victory Jerv in the table in the 1st division.
Sindre Tjelmeland’s team had three straight losses in the series and cup before Friday’s battle.
Jerv, on the other hand, had delivered three straight victories in the series, although there was also a cup exit for the Grimstad team in this period.