Dundee United blew the chance to go into the New Year on top of the Championship as Dumbarton weathered a second half storm to claim three crucial points in their battle to beat the drop.
Leading by Mark Docherty’s long-range strike, the Sons faced a barrage of pressure in lashing rain and a strongly gusting wind but they held firm to send the visitors crashing to their first league defeat since September.
In the process Stevie Aitken’s part-timers completed a memorable double, having also beaten the Taysiders at the same venue on the second Saturday of the season.
Disappointed United boss Ray McKinnon refused to make excuses for a sub-standard display but said: “It’s a strange, freakish goal that’s beaten us.
“Everyone has missed it because of the wind so that was frustrating. We’re not making excuses but that was horrific weather to play football in and to ask your players to be extremely technical is difficult.”
The Tannadice boss added: “We’ll just take it on the chin and move on. There were some that were below par today and there was a lack of quality.
“It wasn’t until we put Mark Durnan up there that we had a goal threat – it’s disappointing when your centre-half becomes your biggest goal threat.
“We’ve had a great run – three months unbeaten and sometimes football is like that and you just have to accept it and move on.
“You always have another game coming up and we just need to lift our standards again.”
Conditions made it difficult for the players and it was the home side who were quicker to adjust, forcing the first save of the game when Mark Docherty tried his luck from distance but Cammy Bell was equal to it.
Bell had a much more anxious moment when Sam Stanton’s effort drifted narrowly wide with the United keeper stranded.
The visitors had little to offer and they could have had few complaints when Dumbarton made the breakthrough on 27 minutes.
It was a bizarre affair as Docherty’s looping cross from wide on the left fooled everyone in the box and bounced high into the top corner of the net with Bell helpless.
The goal finally stung the Tayside team into action and they carved out their first shot on target through Stewart Murdoch, whose effort was saved by Alan Martin.
But the Sons looked just as likely to double their lead and they almost did just that when a fierce shot from Joe Thomson fizzed inches wide.
Martin then produced a fingertip save to deny Willo Flood before Dumbarton survived a scare when Simon Murray forced the ball over the line in a crowded home box – but his effort was ruled out for offside.
Josh Todd saw a goalbound shot blocked as the Sons pressed for the comfort of a second goal on the restart but United gradually began to dominate possession and create chances.
They were almost level when a Scott Fraser corner took a wicked deflection and rebounded from the crossbar. Then Docherty produced a vital last-ditch interception to prevent Fraser’s cross from reaching Nick Van der Velden.
Fraser sent a 30-yard free kick just over as United’s efforts to find an equaliser grew increasingly desperate. And the Tangerines knew it wasn’t to be their day when a stoppage time header from Mark Durnan rebounded from a post.
Jubilant Sons boss Aitken declared: “It was a terrific performance and result and we had to dig really deep in the second half. It shows the character of the players to do it against the league leaders.
“They were always going to put us under pressure in the second half. They have quality in their side, right throughout, and I can’t even fill a bench.”