Tommy Woodward and keeper Jack Stanbridge proved to be Horndean’s FA Vase heroes.
The duo played key roles as Dave Carter’s men edged out Willand Rovers 4-3 after extra-time.
In a Vase thriller, Stanbridge – making his Horndean debut – saved a penalty in the first period of extra-time.
That set up the decisive moment, as Woodward then popped up with a late winner.
‘It was a great game and outstanding result for us,’ said Horndean manager Carter.
‘That puts us five games from Wembley and earned us £1,200.’
Chamal Fenelon and Dan Hayes gave the home side a flying start against the run of play.
But the Western League side hit back to level it at 2-2 at half-time.
Woodward restored the home side’s lead with a 70th-minute free-kick but the visitors levelled again soon afterwards.
The game went into extra-time after Gavin Spurway missed an open goal in the last minute.
In the Wessex League premier division, Fareham Town crashed to a disappointing 3-0 defeat at Alton Town.
The Reds missed an early penalty, then conceded two spot-kicks in the second half.
They also had Wayne Boud sent off.