An 89th-minute goal from Melbourne City's Nicolas Gonzalez proved decisive in his side's 2-1 win over Melbourne Victory in the Foxtel National Youth League on Sunday.
Lawrence Thomas took his place between the posts as the only overage player for the visitors, while George Howard joined Joey Katebian up front.
Christian Cavallo was a late inclusion for Scott Galloway, who sustained an injury in the lead-up to kick-off.
City wasted little time taking the ascendancy as Christopher Cristaldo did the damage, timing his run to perfection before slotting past a helpless Thomas.
Victory had to weather a nervy 30-minute period as the hosts played some enterprising football, though Thomas was on hand to thwart Philip Petreski, Luke Gallo and Denis Genreau respectively.
Victory finally kicked into gear though and would have equalised through Howard's acrobatic effort but for a sharp save from Jack West-Astuti.
Things continued to improve after the interval and Melbourne was finally rewarded for its efforts. Anthony Duzel's diagonal ball on the edge of the area slipped Katebian through, the captain making light work of sending the ball in at the near post.
Duzel was involved again not long after, going close to edging his side in front with a glancing header at the far post.
Katebian then went agonisingly close to adding a second, after being unable to keep down Howard's delightful ball from the right. Howard was provider again for Pierce Waring, who could not steer his shot on target.
The visitors paid the ultimate price of their inability to close the game down when Gonzalez pounced on a Stefan Zinni delivery to net the winner.
Melbourne will have to wait 13 days until its next fixture, when it faces Adelaide United at Lakeside Stadium.
Melbourne City 2 (Cristaldo 7', Gonzalez 89')
Melbourne Victory 1 (Katebian 54')