Seaham Red Star boss Mark Collingwood quit after his side endured an FA Vase exit at West Auckland Town on Saturday.
But the club have acted quickly to name his assistant, Chris McCabe, as replacement.
Red Star came back from a two-goal deficit – but eventually lost the first preliminary round 3-2 to West, a week after cruising to a 4-0 Northern League victory on the same ground.
“I did the job I set out to do and felt the club was in a great place,” said Collingwood, who had taken the club up from Division Two in his lengthy reign of more than 200 matches.
“Personal stuff required me to be nearer to home, so that’s my intention. Seaham are left with a great team and they are a proper club.
“I am sad but proud.”
McCabe will take control for the first time in tomorrow’s home Durham Challenge Cup tie against Sunderland West End.
On Saturday, David Edwards and Tommy Marron had West on top with goals inside the opening 19 minutes.
They kept their advantage for the best part of an hour before Robbie Bird threw Red Star a lifeline.
With two minutes left, David Paul levelled to take the tie into extra time, but the home side grabbed the winner, with Ross Gardner scoring to set up a home clash with Padiham in the next round.
Easington Colliery left it late before seeing off Yorkshire visitors Thackley 2-1, clinching a home tie against Ashington.
Jordan Rause gave the visitors an interval advantage and there were just seven minutes remaining when captain Chris Pearson restored parity.
Extra time was on the cards, but, on 88 minutes, young Joe Kerridge delivered a tremendous shot from the edge of the box which gave visiting goalkeeper Matthew Convery no chance.
After holding a two-goal interval lead and then going 3-2 down, Durham City claimed a dramatic 94th minute equaliser at Penrith – but the Cumbrians came out on top after extra time.
Kyle Patton and Jeremy Allen gave the Citizens a perfect start only for the hosts to hit back strongly after the break.
Three goals flowed in quick succession from Andy Murray-Jones (2) and Jamie Street and, with the clock ticking down, a win for Penrith in normal time looked the likely outcome.
But four minutes into added time Patton came up trumps to keep City in the tie.
However, their hopes wilted when Richard Faustino struck in the 104th minute and Jake Smith made it 5-3 with only three minutes left.
Chester-le-Street convincingly outgunned Brandon United 7-0 away to set up a home tie against Norton.
Four goals in the opening 11 minutes had the Cestrians purring. Daniel Bedding, Lee Mole, Dominic Laws and Mark Peck all beat home goalkeeper Tom Orton, who conceded another three in the second half.
Mole completed a hat-trick and Laws claimed his second goal as the visitors enjoyed a stroll in the park.
It wasn’t a good day for Washington, however. They went out to Billingham Synthonia, for whom Max Craggs scored the only goal when he crashed the ball past goalkeeper Graham Pickering early in the second half.
Connor Hughes was an early scorer for Crook Town, but Esh Winning progressed with strikes from Grant Willis and Daniel Robinson.
Bishop Auckland had no trouble beating Bedlington 3-0, courtesy of Andrew Johnson (2) and Priestley Griffiths inside 42 minutes. They next host Billingham Town.
Consett are being touted for a good run and they set up a home tie with Pickering Town when they went nap at home to Hebburn Town.
Luke Sullivan (2), Adam Knowles, Lewis Gibbons and Lewis Teasdale struck, with Channon North claiming a late consolation.
Team Northumbria could also be dark horses. They have made a hugely impressive start in Division Two, with eight wins and a draw from nine games.
They again produced an excellent performance, beating Carlisle City 2-1 thanks to a brace from Ben Dibb-Fuller.
Newcastle Benfield hammered Alnwick Town 8-1, with Scott McCarthy (2), Dylan McEvoy (2), Paul Brayson (2), Mattie Cornish and Mechack Kanda notching.