Mark Bishop’s side pulled a goal back three minutes after the restart through Jade Chapman who met Jess Gray’s corner to head home.
The game was blown wide open in the sixty-third minute when Burgess Hill grabbed a second, as substitute Millie Morley pounced on a loose ball to convert after Newhaven goalkeeper Hannah Paul spilled what should have been a routine catch.
Winchester restored Newhaven’s two-goal cushion six minutes later with a deflected effort from the edge of the area, but they were pegged back once again with twelve minutes remaining when Charley Law poked home for Burgess Hill, evading her marker to convert another Gray corner.
Revitalised by their impressive second-half performance, Burgess Hill searched desperately for an equaliser as the clock ticked down.
They were presented with a golden opportunity in stoppage time when Newhaven ‘keeper Paul let the ball roll underneath her foot as she tried to clear, but she recovered well to eventually collect and deny the onrushing Morley.
However, the crucial eighth goal of the game arrived two minutes later as Newhaven found a fifth. Winchester completed her hat-trick with a fine finish as she darted inside, skipped past two defenders and drilled the ball in at the near post to clinch the trophy for Newhaven and put the result out of sight for Burgess Hill.
Newhaven joint-managers Alex Ladd and Andy Cook were delighted to oversee their team’s successful cup run, with victory in the final extending their season-long unbeaten streak to fourteen matches: “We’ve got the belief in the players, and the players have got the belief in themselves.
“They know they can score goals; they know that they can work hard,” said Ladd.
“We’re just so impressed by them and they’re a great bunch of players,” added Cook.