Beauden Barrett slotted a drop kick after the hooter had sounded to hand the Blues an unlikely 21-19 win over the Brumbies in their Super Rugby Pacific clash at Canberra's GIO Stadium.
The victory was the Blues' 12th in succession this season, equalling the 1997 side's record for most consecutive victories by the team.
What's more, the Blues' win also sees them seal first place in the Super Rugby regular season, and will conceivably give them home advantage at Eden Park for the entire playoffs.
The Brumbies looked certain to close out the victory but a sensational passage of play between the Blues backs gave the first-five the opportunity to seal a famous victory in Canberra.
The hosts raced out of the blocks with an opening try to Pete Samu after winning a lineout against the Blues throw. The loose forward cleverly placed the ball against the uprights off the back of the breakdown just a metre out
Both teams struggled early to find continuity in their play, with the opening stanza being dominated by errors and penalties.
Stephen Perofeta scored the Blues' first points with a penalty goal after a series of infringements from the Brumbies defence, before some brilliant play between Mark Telea and Dalton Papalii down the right wing almost sent the former over for the Blues' first try - only to be held up over the line.
Minutes later, Roger Tuivasa-Sheck could've opened his try-scoring account for the Blues but again for some scrambling Brumbies defence to keep him out.
Tempers ran high, forcing the referee to have a chat to both captains after Nic White objected to another penalty being called against his team.
Ill-discipline continued to be the Brumbies' worst enemy, and the Blues looked to have finally made them pay through hooker Kurt Eklund but he lost control of the ball with the line begging.
Brumbies hooker Folau Fainga'a was then shown a yellow card for a no-arms tackle earlier in the passage, before further indiscretions saw lock Darcy Swain also sin binned just minutes later.
The Blues finally made the numerical advantage count through first-five Barrett, who went over off a simple pass and move off the back of a series of scrum resets to give the visitors an 8-7 lead at the break.
The visitors continued to dominate possession in the second half and almost extended their lead through James Tucker after some nice touches by Barrett and Perofeta but a Finlay Christie knock-on brought the play back.
A loose ball almost saw White sprint 50 metres for the try but for an incredible last ditch tackle by Tuivasa-Sheck to keep the halfback out.
It was then the Blues' turn to be on the wrong side of the ref's whistle, conceding back-to-back penalties, allowing the Brumbies to set their maul from a lineout drive and Fainga'a to go over for the try.
Perofeta's off night with the boot continued as he missed a relatively easy shot at the goal posts that would've cut the lead to just one point.
The Blues turned down another shot at three and it paid off immediately with replacement prop, Karl Tu'inukuafe crossing for the try right underneath the sticks. Perefota finally found some form off the tee to convert the try, before nailing a penalty shortly after.
The Brumbies hit back immediately through replacement hooker Billy Pollard as the home team looked set to close out the victory.
But the Blues clawed their way back to the Brumbies try line, earning the penalty advantage from right in front. Christie found Barrett in the pocket and he made no mistake.
The Blues will finish the regular season away to the Waratahs next Saturday, but cannot be overtaken in first place on the ladder before the playoffs.
The previously second-placed Brumbies have dropped to third, thanks in part to the Crusaders' victory over Fijian Drua on Friday night.
Blues 21 (Barrett, Tu'inukuafe tries; Perofeta conversion; Perofeta 2 penalties; Barrett drop goal)
Brumbies 19 (Samu, Fainga'a, Pollard tries; Lolesio 2 conversions)
