Edinburgh sent Glasgow packing from the capital for the second season running as the Gunners took a step towards reclaiming the 1872 Cup with a 23-11 first-leg win.
In front of a record inter-city crowd of 23,642, the hosts at Murrayfield fell behind to Mark Bennett's early try but hit back to win with scores from Matt Scott and John Hardie.
With Guinness Pro12 points also on offer, Alan Solomons' team now leap-frog Glasgow into the top six ahead of next Saturday's Scotstoun return.
Edinburgh's victory in the annual festive double-header 12 months ago ended Glasgow's five-year reign of dominance and injected a dispirited squad with a large dose of self-belief.
And they again put the league champions under pressure as their heavy-duty pack dominated the breakdown exchanges.
Yet Warriors took just seven minutes to unpick the meanest defence in the Pro12 as they started brightly.
Leone Nakarawa and Fraser Brown combined to win turnover ball on halfway before the big Fijian lock drove the visitors into scoring range. With a patient look, Gregor Townsend's team played through a couple of phases before Finn Russell slotted in Bennett to crash over for the opening try. Russell, though, tugged his conversion.
But Warriors failed to build on that positive start and were themselves cut open six minutes later. It was brute force which saw Cornell Du Preez run over the top of Russell as the number eight broke down the right, popping off at the perfect moment to allow Scott to run in for a score in the corner.
Gunners scrum-half Sam Hidalgo-Clyne added the extras as well a penalty before half-time as Glasgow, who also saw Bennett miss a long-range kick, went in 10-5 down.
Russell and Hidalgo-Clyne both traded a couple of kicks each as the opening 20 minutes of the second half saw the teams go blow for blow.
But the longer the match wore on, the more Edinburgh's might in the forward areas told and they finally capitalised with 10 minutes left. Ben Toolis palmed a line-out down for Hardie who virtually staggered over the whitewash as the Glasgow defence disintegrated. Hidalgo-Clyne again converted.
The visitors piled forward in the closing stages looking for a score which would offer a losing bonus-point but the Edinburgh defence, which has conceded fewer tries than any other Pro12 side this season, stood firm for another morale-boosting win.