Troubled Swansea City’s automatic promotion campaign appears in danger of melting faster than the layer of snow that covered Darlington’s pitch last night.
On an evening when skiing seemed more appropriate, Swansea continued on a slippery slope that leaves them outside the top three for the first time since late September.
A third defeat in four games means they drop to fourth, Macclesfield, taking their place by scoring one goal more.
And, having enjoyed a six-point cushion in the top three just a few weeks ago, Swansea will be playing catch up if Macclesfield triumph at Oxford tonight.
Having lost at Mansfield and Leyton Orient and been held to home draws against Southend and Grimsby, what a disastrous month this has been.
Throw in the fact midfielder Andy Robinson is due in court tomorrow after being charged with a public order offence for an alleged incident in Swansea at the weekend, and Jackett has his fair share of problems.
Having said that, the Swans did not deserve to lose on an evening when heavy snow presented a different kind of obstacle to their promotion challenge.
The wintry conditions had left the Williamson Motors Stadium surface in a terrible condition, any green areas left exposed before the interval disappearing under another half-time blizzard.
But both sides adapted well, and Swansea produced a solid performance.
Honours were even at the break after Adrian Forbes cancelled out Matt Clarke’s 35th-minute opener.
But Darlington just about shaded the second half and gave their play-off hopes a major shot in the arm when Neil Wainwright scrambled a winner six minutes from the end.
It leaves Swansea in the worst possible condition for Saturday’s visit of second-placed Scunthorpe, though the fact Brian Laws’ men went down 4-3 at Yeovil might offer a crumb of comfort.
As if Swansea dropping two points against Grimsby at the weekend had not been frustrating enough, Jackett’s week began with news of Robinson’s arrest.
Unsurprisingly, with a court appearance looming, the Scouser was left out for the trip north.
That made it easy for Jackett to hand new signing Kevin McLeod his first start in midfield.
With Paul Connor missing with a dead leg, Lee Trundle operated as a lone striker as Jackett played five across the middle to match Darlington in that department.
Leon Britton was the man to benefit from Connor’s absence.
The covers had been removed a couple of hours before kick-off, but at the start the pitch still had a thin layer of snow across it.
And the conditions threatened to get progressively worse as the two teams were welcomed onto the pitch by the icy blast of a fresh blizzard.
There was also a flurry of early chances, Trundle extricating the ball from the white stuff beneath his feet to thump a 20-yard shot against a post four minutes in.
Darlington then sent a shiver down Swansea spines when Mark Convery drilled an 18-yard effort across the slippery surface to test Willy Gueret’s handling skills, and soon after the Swansea No 1 was called upon again to flick away a dangerous Neil Wainwright cross.
Quakers keeper Sam Russell also showed impressive agility when he leapt acrobatically to turn another terrific Trundle effort out for a corner as, apart from the odd slip or slide, both sides took to the testing conditions like polar bears to the Arctic snow.
But Darlington were first to celebrate after winning a free-kick 20 yards out and to the right of Swansea’s penalty area.
Former Celtic man Bobby Petta delivered a perfectly weighted ball to the edge of the eight-yard box and Clarke ran in behind the Swans defence to glance it past the helpless Gueret.
Darlington’s lead lasted just three minutes, however.
Swansea drew level when Britton won a bone-crunching tackle in midfield and sent Marcus Bean down the left, the on-loan QPR man rounding the keeper and crossing from the byline for Forbes to convert from close range.
Swansea might have gone into the interval 2-1 up had Trundle showed a little less selfishness.
After chesting down a long pass out of defence, turning and then running some 20 yards, he probably felt entitled to shoot but McLeod was better placed to his left.
As it was, Trundle produced a shot too tame to trouble Russell.
Four minutes into the second period and McLeod, enjoying an enterprising full debut, was guilty of squandering a great chance.
The Scouser capitalised on hesitancy in the Quakers rearguard, but succeeded only in drawing a smart sprawling save from Russell with a shot placed straight at the keeper.
Darlington were making more of a nuisance of themselves in the final third of the pitch than the visitors.
Referee Colin Webster – bizarrely based just up the road in Tyne & Wear – enraged the home fans by denying what they saw as fair claims for a penalty and a free-kick for handball deep in Darlington territory.
The small pocket of visiting fans were also doing their best to rouse Swansea and Jackett did likewise by withdrawing Forbes for Lee Thorpe.
But it was to be a night Darlington, not Swansea, gave their promotion hopes a major boost.
Six minutes before time, Petta delivered another delicious set-piece that Swansea failed to clear and Wainwright got the final touch on a frantic scramble.
Bean saw a header cleared off the line by Mark Convery as the Swans battled in vain to force a late equaliser, but the big freeze continues.