Edinburgh (16) 16
- Try: Fife
- Con: Laidlaw
- Pens: Laidlaw 3
Stuart Hogg's second-half try earned Glasgow a morale-boosting Murrayfield victory in the first leg of their 1872 Cup tie against rivals Edinburgh.
That had looked unlikely for most of the match as Alan Solomons' capital side were the more dominant and had led from Dougie Fife's first-half score.
Duncan Weir kept the Warriors in touch with five penalties.
And their determined defending was rewarded when Hogg's try earned them a first-leg lead and four Pro12 points.
Gregor Townsend's side have won the 1872 Cup - contested over their two league meetings - for the last four years but they knew a resurgent Edinburgh were not only capable of beating them, but of overtaking them in the Pro12 table with two wins in the festive derby double-header.
Instead, victory lifted Glasgow into
third place in the table,
and 11 points clear of their Scottish rivals.
Weir kicked the visitors ahead after Edinburgh had been penalised for not rolling away after a tackle.
But Glasgow prop Ryan Grant was penalised in the scrum, allowing Greig Laidlaw to score the first of his three penalties before Weir's confident swipe from a subsequent penalty put Glasgow 6-3 ahead.
Edinburgh have enjoyed a Heineken Cup win over Gloucester and a Pro12 victory over Leinster recently as Solomons begins to reap the rewards of his efforts since taking over in the summer.
Certainly, they looked the more confident in attack and deserved to move ahead after quarter of an hour when Laidlaw fed the ball out to the right to initiate a brisk attack, which culminated in Fife crossing the line after receiving Jack Cuthbert's pass inside.
Laidlaw made no mistake with the conversion.
Edinburgh captain Greig Laidlaw must lift his team-mates for the Glasgow return leg
A Weir penalty reduced the margin to one point but his team were stung twice in quick succession when first flanker Tyrone Holmes was sin-binned, rather harshly, for clearing out Laidlaw when the ref deemed that the scrum-half did not have his hands on the ball, and secondly when the Edinburgh skipper slotted over a 40m penalty.
At 13-9 down, Glasgow were still in contention but rarely looked like piercing the black and red line.
Their captain Chris Cusiter tried to generate some lively attacks from the breakdown but the likes of winger DTH van der Merwe and Hogg, playing at centre rather than full-back, were too peripheral to the action.
Nor did Townsend's side look to have anyone playing with the desire of Edinburgh's David Denton or Roddy Grant, who led the hosts out on his 100th appearance for the club.
Edinburgh built up a head of steam and, had Denton not got carried away and come in from the side of a ruck, while off his feet too, they might have finished their impressive assault on Glasgow's try line.
As the half wore on a double sin-binning had the Murrayfield crowd roaring their disapproval.
To most spectators, the wrestling match over the advertising hoardings more closely resembled a spat from Tom Brown's schooldays than the Edinburgh wing's tussle with Hogg, but both players were yellow-carded.
Edinburgh blew the chance to punish the 13 men when Cuthbert knocked on five metres from the try line as black shirts lined up to score in the corner but they were soothed when Laidlaw's penalty gave them a 16-9 half-time lead.
There were good exchanges on the resumption with Fife powering down the right wing and Denton down the left before being halted.
At the other end, the re-instated Hogg made his first threatening move of the match, a jinking run spreading panic.
Weir was wild with a pass out to the left as Glasgow at last enjoyed a sustained attack but made amends with a penalty, that following a thrilling Cusiter up-and-under into the goal area that came to nothing.
Laidlaw arrowed a long-range penalty under the bar and Fife was again knocked into the sidelines as he moved like a steam train down the right wing.
Yet for all their apparent superiority to that point, Edinburgh found themselves leading Glasgow by a mere point when Weir's fifth penalty sailed through the posts.
And, held together by superb defending, the Warriors' completed their turnaround when, after a flowing move, Hogg ran 40m to pounce on Van der Merwe's delightful clipped kick through from the left wing that caught out the Edinburgh defence.
Weir's attempted conversion from an acute angle went wide to leave it 20-16 to the Warriors with 12 minutes to go.
The bulk of the 10,000 fans urged the home side on but Glasgow again held firm and they are in a strong position to retain the 1872 Cup when Edinburgh travel to Scotstoun Stadium for the return leg on New Year's Day.
Cuthbert, Fife, De Luca, Atiga, Brown, Tonks, Laidlaw, Blaauw, Ford, Nel, Gilchrist, Atkins, Du Preez, Grant, Denton.
Beard for Brown (47), Coman for Grant (60). Not Used: Lutui, Allen, Cross, van der Westhuizen, Hart, Fenner.
Maitland, Seymour, Hogg, Dunbar, van der Merwe, Weir, Cusiter, Grant, MacArthur, Welsh, Swinson, Ryder, Harley, Holmes, Wilson.
Jackson for Seymour (28), Hall for MacArthur (40), Low for Welsh (51), Nakarawa for Swinson (59), Fusaro for Holmes (60), Strauss for Jackson (43). Not Used: Reid, Pyrgos.
Holmes (26), Hogg (36).
Neil Paterson (SRFU).
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