The White eagles stole victory over Blacktown City, after a goal-keeping mistake gave them the single goal in the match, ensuring a 1-0 victory at Bonnyrigg Sports Centre.
Nikola Zonjic was the match winner, bundling the ball home when Blacktown City keeper Blake Tuxford spilled the ball from a Chris Tadrosse corner.
The Bonnyrigg defender was on the spot to take advantage of the mistake, prodding the ball home shortly before the hour mark.
Bonnyrigg could have scored more, but Tuxford was otherwise superb and the young goalkeeper distinguished himself on a number of occasions, making some fine saves.
The first chance of the match fell Blacktown City's way and on another day it would have been buried without second thought. Sasa Macura's run took him to the byline and when his cut-back found Ryuiji Miyazawa but his connection was not true and Bonnyrigg keeper Matthew Nash recovered well to make a superb save to his right.
Bonnyrigg began to feel their way into the game and there was 20 minutes on the clock when they carved an opportunity. Aaron Peterson fed Terry McFlynn, who looked awkward and out-of-position on the right of midfield all night, and his cross found the head of Younis. The Bonynrigg forward was unable to keep his header down.
On the half hour Robbie Younis smashed a dipping right footer at goal from 25 yard out that looked destined for the back of the net. Tuxford showed superb judgement to read the flight of the ball and tip it over the bar.
The sides headed to the sheds level after a 45' minutes that was often bogged down in midfield and mired in caution.
Immediately after the break, Alex Mansuetto lashed a shot at goal from distance that Tuxford repelled, the keeper springing high to his right to touch the ball over the bar.
Bonnyrigg was showing much more intent in the second stanza and they were rewarded with their goal in the 57th minute.
Tuxford will not want to look back at it for it was not a moment for which he will feel any fondness, but once he spilled the ball, Zonjic was on hand to punish the error.
He showed great resilience to not let the error effect his concentration though, and he made another superb stop to deny Ken Chun's well struck shot.
Mark Crittenden sent on Danny Choi and he looked lively, forcing Mansuetto to concentrate on defending, which he did well.
Choi had a shot on his weaker right foot that was stopped comfortably by Nash and Peterson dragged a shot wide from a good position, but it was one goal that decided the match between two evenly matched sides who are sure to meet when the whips are cracking in the finals.
Bonnyrigg White Eagles 1 (Nikola Zonjic 57')
Blacktown City 0
Saturday August 2, 2014, Bonnyrigg Sports Centre, Bonnyrigg
Referee: Stephen Lucas
Assistant Referees: Adam Coombes and Mitchell Clark
Fourth Official: Adam Vainauskas
Bonnyrigg White Eagles: 1.Matthew Nash; 2.Alexander Mansuetto, 4.David Vrankovic, 5.Chris Tadrosse (C), 6.Nikola Zonjic, 9.Robbie Younis (16.Howard Fondyke 85'), 12.Dylan Fox, 18.Adrian Ucchino,19.Aaron Peterson (26.Jordan Crighton 90+2'), 21.Ken Chun, 35.Terry McFlynn (8.Alexander Canak 57')
Substitutes not used: 20.Tristan Prendergast, 11.Benjamin Spruce
Yellow Cards: Adrian Ucchino 69'
Red Cards: Nil
Blacktown City: 13.Blake Tuxford; 3.Giorgio Speranza, 5.Jacob Poscoliero, 7.Travis Major (C), 8.Sasa Macura, 9.Ryuiji Miyazawa, 10.Shayne D'Cunha (17.Kieren Paull 79'), 14.Mitchell Mallia, 16.Kearyn Baccus, 18.Daniel Araujo (11.Danny Choi 65'), 19.Zac Cairncross
Substitutes not used: 1.Nenad Vekic, 4.Lewis Beumie, 12.Joel Hardwick
Yellow Cards: Zac Cairncross 59'
Red Cards: Nil