South Australia has blown a chance to move closer to another national U18 title after a last quarter fade out against Vic Metro at Football Park on Sunday.
SA, which had beaten the Allies and WA in the first two rounds, led by 35 points at three-quarter-time but did not add any goals in the last term.
Vic Metro co-captain Andrew McGrath inspired his side to the thrilling three-point win.
The 179cm half-back, who won the Australian under-17 400m hurdles title in 2014, displayed his elite running speed and accumulated 27 touches, six marks, six rebound 50s and three tackles.
Midfielder Dylan Clarke, the younger brother of North Melbourne draftee Ryan, showed why he is an integral member of Vic Metro's onball unit with 24 disposals, nine clearances, five tackles and a goal.
Hard-running midfielder Daniel Venables impressed with his overhead marking and skills at ground level, finishing with 16 touches, nine tackles and two goals, including one major in the tense final term.
With Vic Metro trailing by 35 points at the last break, forward Patrick Kerr sprung to life after being inaccurate in front of goal in the first three quarters (0.4), bagging four majors in the space of 10 minutes and ending with nine touches and eight marks.
Two of Kerr's final-quarter goals came tight on the boundary on the wrong side for a right-footer, while 193cm Jack Scrimshaw rounded out Vic Metro's leading ball-winners with 22 possessions.
For South Australia, 187cm left-footer Sam Walker worked tirelessly in defence once again and generated constant counter-attack across half-back with 21 touches and seven rebound 50s.
Running defender Alex Villis also made good decisions and was rarely beaten in one-on-one contests on his way to collecting 18 possessions, six inside 50s and four tackles.
In attack, 186cm Will Hayward kicked three goals for SA and read the flight of the ball well, while midfielder Jake Pitman had 29 disposals, four marks and booted a goal in a strong display.
Vic Metro stormed home with a six-goal-to-nil final quarter to claim the remarkable win.
The result leaves Vic Metro, South Australia and Western Australia all in contention to take out the NAB AFL Under-18 division one crown.
SOUTH AUSTRALIA 2.1 6.3 10.4 10.6 (66)
VIC METRO 0.5 2.9 3.11 9.15 (69)
GOALS
South Australia: Hayward 3, Houlahan 2, Lebois, Nixon, Graham, Fogarty, Pitman
Vic Metro: Kerr 4, Venables, Florent 2, Clarke
BEST
South Australia: Pitman, Hinge, Walker, Villis, Slimming
Vic Metro: McGrath, Clarke, Venables, Romensky, Kerr
