Mick Catlin admitted his frustration after coming within seconds of a first win in charge of Gosport Borough.
The Privett Park hosts were knocked out of the Southern League Challenge Cup on penalties by neighbours Moneyfields.
That was after they surrendered a 2-1 lead in the dying moments to a stunning strike from former player Sam Pearce.
Catlin, who began his reign with a 3-0 defeat to Hitchin Town on Saturday, said: ‘I can take some encouragement because I thought we did enough to win.
‘It is frustrating as we were the better side.
‘But if you don’t manage the final minutes of the game then you get punished.
‘If we had taken our chances in the first half it might have been different.
‘We played well in spells but have to keep it up for the whole game.
‘It was a great strike from Sam at the end, though.’
Moneyfields goalkeeper Steve Mowthorpe pulled off a terrific point-blank save to deny Sam Woodward in the opening three minutes.
Soon after, he prevented his side falling behind again with an equally good stop from Frankie Paige.
Borough finally found a way through on 25 minutes with Curt Watts turning in a deep cross from the right.
Moneys equalised on 35 minutes – Ryan Pennery firing past Lewis Watch.
But Borough regained the lead three minutes later when Iffy Onwuachu challenged Mowthorpe and somehow the ball rolled into the net.
Watch had to get his body behind a long-range effort from Gavin Spurway early in the second half.
The Gosport keeper also did well to hold a fierce Joe Briggs drive.
Watch then pulled off the save of the night on 80 minutes – showing great reactions to block Gary Austin’s close-range shot.
But Moneys did snatch a 92nd-minute equaliser.
Substitute Pearce rifled home an unstoppable shot to send the game to penalties.
He then kept his cool to convert the winning spot-kick in a 4-3 success.
Fareham Town beat visitors Newport 2-1 in the Wessex League premier division.