An injury time penalty rounded off a spectacular afternoon of football at Highbury
Fleetwood were ahead after just 18 seconds, a determined Steven Schumacher stealing it from the feet of Alan Marriott to set up Gareth Evans.
But Mansfield hit back within ten minutes - a free kick conceded on the edge of the box Chris Clements firing low into the far corner.
A howler from Ryan Cresswell then handed the Stags the lead, his mis-kick teeing up Anthony Howell to smash the ball home.
It was end to end stuff and Fleetwood were able to pull it back to all square before the break, Sarcevic taking a tumble under Martin Riley’s challenge, the midfielder converting from the penalty spot.
Fleetwood found their way back in front early in the second half, a superb run from Sarcevic ending on the edge of the box, his shot taking a deflection on the way to the bottom corner.
Evans grabbed his second two minutes later, the home side breaking quickly from a Mansfield corner, the winger with a 20 yard curling effort.
Sam Clucas ensured the Stags were still in it, stabbing home a loose ball to give the visitors hope.
And Ross Dyer produced an incredible late leveller, in the right place at the right time to turn home after Conor McLaughlin could only half scramble Sam Clucas’s effort away.
But there was more drama to come, Matty Blair brought down by James Jennings, a second penalty, Antoni Sarcevic cool as you like to seal his hat-trick and victory for Town.
Graham Alexander was left frustrated by poor defending despite the win.
“If we had have drawn that game it would have felt like we lost,” he said.
“We lost it twice.
“We were fortunate to take the lead in the first minute, it was a poor goal for them to concede.
“But we’ve gifted them two goals, then got ourselves back in it.
“We’ve started again after half time, played great, got to a 4-2 lead, needed to play the game out but let them back in again.
“Credit to Mansfield, they never gave up.
“It was two teams going full at it attacking wise but both managers will say, defensively, they can do better.”
Town travel to in-form Accrington Stanley on Tuesday.