Dundee United returned to the bottom of the Premiership following a contentious 1-0 defeat against Motherwell.
Sondre Solholm Johansen notched the only goal of the game, with the returning Mark Birighitti unable to block his powerful header.
Debate raged when Tony Watt was sent off for a high challenge on Sean Goss before the break, with John Beaton acting following an intervention by VAR.
A third successive defeat in all competitions sees United slip to the foot of the table on goal difference behind Ross County, who host Hearts on Sunday.
Key moments
Steven Fletcher fired inches wide with a stunning scissor-kick – the most dangerous moment of a bright start which saw United win four corners in the opening 10 minutes.
However, Motherwell were always a threat on the break.
Birighitti made a sharp save to deny Connor Shields after Matthew Penney had surged through the heart of the Tangerines back-line with alarming ease.
Shields then smashed over the bar from point-blank range following a lightening counter-attack; a huge missed opportunity.
The Steelmen would not be denied when ex-Terror Blair Spittal was given too much room to cross and Johansen’s header bounced over the line despite Birighitti getting a hand to the effort. It was the fourth successive strike United have conceded in the same manner.
Things went from bad to worse for the hosts when Watt was dismissed for a high tackle on Goss, with referee John Beaton making the decision after a trip to the VAR monitor.
In the circumstances, United began the second half in promising fashion. Ian Harkes forced a superb near-post save from Liam Kelly after a fine Fletcher knock-down.
While Aziz Behich lashed a right-footed effort over the bar, Fox’s charges failed to carve open their visitors.
United star man: Jamie McGrath
McGrath impressed on another grim afternoon for United.
He created three chances for the hosts – more than any other player on the pitch – and enjoyed an effective, combative partnership with Craig Sibbald in the heart of midfield.
United appear to have solved their issues in the engine room. The wide areas, however, are a different matter.
The Ireland international was moved to a more advanced role following Watt’s red card and repeatedly attempted to bring the hosts to life with surging runs forward.
Player ratings
Dundee United (3-5-2): Birighitti 5; Smith 5, Edwards 6, McMann 5; Freeman 5 (Anaku 76), Sibbald 7, McGrath 7 (Pawlett 78), Levitt 4 (Harkes 45, 5), Behich 6; Fletcher 6 (Middleton 74), Watt 4.
Subs not used: Eriksson, Graham, Niskanen, Djoum, Meekison.
Manager under the microscope
Seeking to bounce back from successive 2-1 defeats against Kilmarnock and St Mirren, boss Fox rung the changes and made a couple of huge calls.
Among four alterations to the side beaten by the Buddies, Birighitti replaced Carljohan Eriksson between the sticks; his first appearance since a 4-1 collapse at Hearts in August.
Kieran Freeman, Levitt and Fletcher also came in for Immi Niskanen, Arnaud Djoum and Glenn Middleton, with Fox switching from 3-4-3 to a 3-5-2.
Fox was afforded the unenviable task of masterminding a comeback at 1-0 down and a man light following Watt’s dismissal.
Chasing parity in the last 15 minutes, Fox brought on Middleton and Sadat Anaku in a 3-4-2. However, there would be no way through.
Meanwhile, the repetitive nature of the goals being conceded by United will only put more onus on the boss to fix a hugely damaging issue.
Man in the middle: John Beaton (VAR: David Munro)
VAR took centre stage prior to the break when Watt was given his marching orders.
Despite on-field referee John Beaton not deeming the United striker’s challenge on Goss to be a foul, he was urged by the team in Baillieston, led by David Munro, to view the decision again.
Upon review, Watt’s high, studs-first challenge was deemed a red card offence, despite the former Celtic and Hearts man appearing to make little contact and seemingly attempt to pull out of the tackle.
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