Jamie De Abreu's well-taken finish in the first half of extra-time sealed a memorable win for the National Premier Leagues Victoria club.
0-1 (Rideout 48')
City captain Matthew Halliday started the move that led to the opener by picking out Anthony Costa, who swept the ball out wide to the overlapping Shannon Day. The left-back whipped it back across the face of goal and Alex Rideout was left with the simplest of finishes, tapping home unmarked from the centre of the penalty area.
1-1 (Wallace 88')
Christian Cavallo's corner was met perfectly by the head of Wallace, who powered the ball off the underside of the crossbar, leaving goalkeeper Ryan Veitch no chance. It was no less than the skipper deserved after a tireless performance in midfield.
2-1 (De Abreu 103')
Substitute Patrick Avice gathered a loose ball on the edge of the area and nudged it wide to De Abreu, who cut back inside and fired a low shot beyond Veitch.
Although he would ultimately prove to be the hero, De Abreu had already nearly won it almost immediately after his team's equaliser, blasting a strike over the bar from just inside the area. Joel Allwright, a stand-out performer for the away side, then had a shot on target saved by Greens goalie Alastair Bray with the last kick of regulation time.
Adelaide's Anthony Costa had the hosts worried in the 11th minute, demonstrating his strength and skill to shrug off three attempted challenges and unleash a shot on goal, only to see it fly harmlessly high and wide. It was a sign of things to come, with the powerful young centre-forward a regular threat for the away side.
Green boss John Anastasiadis would have had his head in his hands on 25 minutes when Liam McCormick drove toward goal and reached the by-line but tried to shoot from an impossible angle, rather than cut the ball back with two team-mates screaming for it on the edge of the six-yard box.
Fortunately for a packed house at the Kingston Heath Soccer Complex, the home side would make amends for their early profligacy and keep their Cup dream alive.
The Final Word
Bentleigh's reward is to host A-League opposition in the semi-finals, with the club's collective fingers crossed tightly for what would be a mouth-watering derby against Melbourne Victory, if Kevin Muscat's men get past Perth Glory.
Bentleigh Greens: Bray, Matthews, Cumming, Webster, Cavallo, Pilkington, McCormick (Avice 79'), Wallace, De Abreu, O'Dea (Teichman 73'), Gallo.
Adelaide City: Veitch, Blefari, Halliday, Mullen, Day, Allwright, Love, Tobias (Acton 106'), Rideout (Sunasky 69'), Budin (Bucco 60'), Costa.
Scorers: Rideout (48'), Wallace (88'), De Abreu (103')
Red cards: N/A
Yellow cards: De Abreu (27'), Rideout (46'), Bucco (63'), Webster (74'), Cavallo (95')
Conditions: 16°C, dry
Attendance: 1,992@Kingston Heath Soccer Complex