Edinburgh continued their climb up the Magners League table with their fourth victory in a row at the expense of Cardiff Blues.
Despite being reduced to 13 men in the latter stages of the first half, they held on to win 11-10 and, guided by the control of Mike Blair at scrum-half, came back in the second period to fully deserve their third win in four years at Cardiff Arms Park.
The Blues had all the early territorial advantage but Edinburgh shocked them with a seventh-minute try after a loose clearance kick was brilliantly exploited by Simon Webster who showed great pace before putting fellow wing Andy Turnbull over in the far corner.
The Blues were making heavy weather of turning their superiority into points with too many unforced errors and turnovers.
Edinburgh's defence held out a succession of attacks, even after centre Nick De Luca was yellow carded for persistent infringements in the 30th minute.
Only when Edinburgh lock Matt Mustchin followed him to the bin four minutes later did the home side take advantage.
From a five metre scrum the Scots were pushed off the ball and Blues number eight Xavier Rush powered over for Ben Blair to convert and give the Blues a 7-5 interval lead.
In the difficult conditions ball retention had become a lottery but it was Edinburgh's turn to have their best attacking spells.
Their patience paid off in the 55th minute when the Blues were penalised in their own 22 and Phil Godman kicked the goal to put his side ahead.
The Blues came back with a penalty of their own by Ben Blair after a great charge by John Yapp.
But the visitors were not to be denied and five minutes from the end got back into the home 22 and Godman coolly dropped the vital goal to seal a well-deserved victory.
The RBS 6 Nations Championship 2015 was not poised to go down as one of the more "vintage" Championships, though there was great anticipation as the action headed into its final day. What transpired was something that nobody could foresee: "The Greatest Day in Rugby's Greatest Championship."