After keeping control of first place for much of Season 11, Hamilton have fallen as Shortland ousted the defending champions 8-4 in a tight affair on Thursday evening.
The vital two points for the Scotchies puts them two ahead of Hamilton, and a resurgent Waratah, as the final round looms next week, and the potential for a quarter-final bye for the new organisation is becoming a real possibility after their major victory.
Hamilton and Shortland began the first half at a slow, but controlled pace, with Shortland heading into the half break with just a single set lead after a key sudden-death decider round put them ahead.
Hamilton were able to claw back into the contest early in the second half with a sudden death victory of their own, but Shortland weren't to be denied as they smelled blood in the water - the Scotch Fingers controlled the tail-end of the second half to keep the Stags to just that single set win, and deliver them their third defeat of the season.
Interestingly, the second defeat in as many weeks for Hamilton is the first time since Season 6 since the champions went winless in more than a single game - the Stags drew with Waratah in Round 9 of the sixth season before copping a 9-5 defeat at the hands of a Benjamin McIntyre guided Cooks Hill to close out the regular season.
Even further back, the first time Hamilton have been delivered two defeats back-to-back was in Season 5 when they were defeated four times in a row - losing to Cooks Hill, The Junction and Warners Bay before falling to eventual champions Waratah 7-4.
That season saw the Stags upset in the quarter finals by The Junction, 9-8, and with that streak snapped many of the title hopefuls in Season 11 may be looking to take advantage of the stumbling Hamilton outfit.
Elsewhere on Thursday evening, Waratah defeated Kotara, 10-4, to move level with the Stags and lock their aim onto a quarter final bye for the upcoming finals.
Raymond Terrace also scored a 14-6 victory over Bar Beach to keep in the race for the top six, while Belmont were downed 9-10 by Cooks Hill in a cagey clash that sees the Beavers tumble from a potential first or second seed down to fourth with just a round remaining on the regular season calendar.
STANDINGS: Shortland (35), Hamilton, Waratah (33), Belmont (31), Raymond Terrace (23), Kotara, Cooks Hill (19), Bar Beach (15).
RD4: Shortland stay undefeated with fourth win (22/03)
RD3: Hamilton claim revenge in grand final rematch (15/03)
RD2: Bar Beach hold off Glendale to bag first win (08/03)
RD1: Waratah sweep aside arch-rivals with major margin (01/03)
PRESEASON: Season 12's draw & key fixtures revealed (08/02/19)
PRESEASON: Rego now open for NDL Season 12. (01/02/18)
GF: Belmont edge out Hamilton in two-set grand final epic (16/11)
FINALS: Hamilton and Belmont set up grand final rematch (9/11)
RD14: Waratah down Belmont in heated one-set thriller (2/11)
RD13: Shortland oust Hamilton from first with one to go (26/10)
RD12: Belmont upset Hamilton to blow first place race open (19/10)
RD11: Shortland take second after thriller against Belmont (12/10/18)
RD10: Waratah tumble into fourth place after slow start (5/10/18)
RD9: Top four teams hold off finals-hopefuls (28/09/18)
RD8: Hamilton claim first as league celebrates Ladies Day (21/09/18)
RD7: Shortland and Kotara clash goes down to the wire (14/09/18)
RD6: Waratah keep close on Hamilton's heels (07/09/18)
RD5: Hamilton prevail in grand final rematch (30/08/18)
RD4: Belmont tumble into ladder mix with defeat (24/08/18)
RD3: Waratah cuts Shortland's undefeated streak short (17/08/18)
RD2: Shortland break Terrace to continue strong start (10/08/18)
RD1: Waratah open account against long-standing rivals (03/08/18)
PRESEASON: Season 11's draw & key fixtures revealed (19/07/18)
PRESEASON: Registrations now open for NDL Season 11. (13/07/18)
GF: Hamilton extend dynasty with fifth championship (06/07/18)
SF: Belmont punch ticket to season decider with comeback (29/06/18)
QF: Raymond Terrace scores maiden finals victory (22/06/18)
RD15: Waratah confirm second place, first week bye (15/06/18)
RD14: Waratah steady the ship with key three-set win (08/06/18)
RD13: Belmont ensures the Waratah slide continues (01/06/18)
RD12: Cooks Hill and Belmont remain level with draw (25/05/18)
RD11: Waratah lose sight of first place after defeat (18/05/18)
RD10: Raymond Terrace shock Cookers in sudden death (11/05/18)
RD9: Cookers drop 'Tahs to second with 6-5 slug-fest (04/05/18)
RD8: Hamilton take revenge in Battle of Oakdale (27/04/18)
RD7: Bailey best on field as 'Tahs in cruise-control (20/04/18)
RD6: Waratah break three-year hoodoo over old rivals (13/04/18)
RD5: Hamilton reclaim first place with 13-0 masterclass (06/04/18)
RD4: League's closest round sees 'Tahs take top spot (23/03/18)
RD3: Cooks Hill record first point with 5-5 draw (16/03/18)
RD2: Sudden-death deciders see Hamilton pip Belmont (09/03/18)
RD1: Waratah-Hamilton classic ends in 6-all draw (02/03/18)