Sunderland undid the good of recent weeks in a 3-0 defeat that did not seriously flatter Swansea City on Saturday but put David Moyes' side under huge pressure in the run-up to Christmas.
Moyes believes the outcome of his side's visit to the Liberty Stadium turned on a "tight" penalty award, when the ball hit Jason Denayer's upper arm as he jumped, in an attempt to block a cross.
Level at the interval, Moyes' team looked capable of going on to win. But from the moment Gylfi Sigurdsson converted the penalty, it was always likelier that Swansea would increase their lead than that the Wearsiders would equalise.
Defensive frailties led to the subsequent goals and the defeat would have been heavier but for Jordan Pickford's saves.
Worse could be to come. Chelsea at home on Wednesday night is probably the last fixture Moyes would want in the hope of a return to the winning form that briefly lifted his team off bottom place.
It was good to see Sebastian Larsson start a game and for Fabio Borini to be on the bench, each after long injury layoffs. Pickford's saves apart, there were no other positives.
The lapses of concentration, weak surrender of possession, multiple errors and lack of punch suggested a return to the bad old ways that earlier this season made relegation seem a certainty.
Manager rating out of 10
4 -- Moyes' job was to motivate the players to at least match the bottom-placed side and this he demonstrably failed to do. His supposedly in-form team was ultimately outplayed by a team that started the day in last place...
Player ratings (1-10; 10 = best. Players introduced after 70 minutes get no rating)
GK Jordan Pickford, 7 -- Not at fault for the goals and pulled off two superb saves to prevent a humiliating scoreline.
DF Billy Jones, 4 -- Did not really do much right. Defensively unsound, he misplaced or underhit passes (one of which triggered the move leading to the third goal) and fluffed an early chance, breaking well in the penalty box but passing poorly when he should have shot.
DF Lamine Kone, 5 -- Some useful blocks but his marking was open to question in some of Swansea's near misses. A long way short of his best.
DF Papy Djilobodji, 6 -- Stuck reasonably well to his task but, after a good first half, was part of the collective vulnerability after the interval.
DF Patrick van Aanholt, 5 -- Another player who looked jaded on Saturday, apart from one or two attempts to set Defoe free.
MF Jason Denayer, 4 -- A liability all over the pitch with poor passing, poor shooting and a poor decision to jump with arms raised at a cross, presenting Swansea with a penalty and the breakthrough.
MF Steven Pienaar, 5 -- Struggled to make a midfield impact.
MF Didier Ndong, 5 -- Started promisingly but faded after picking up a yellow card -- excluding him, on the totting-up process, from the home game against Chelsea -- for a foul committed because his first touch let him down.
MF Sebastian Larsson, 5 -- No hint of glory in his first start since returning from long-term injury. Injuries to Lee Cattermole, Jack Rodwell and now Duncan Watmore oblige him to regain match sharpness quickly.
FW Victor Anichebe, 6 -- Glimpses, but no more, of the strength and vision that have made him a fan favourite.
FW Jermain Defoe, 5 -- A rare display of real disappointment. Had three attempts on goal and ought to have done better with each of them.
MF Jan Kirchhoff, 5 -- Might have been a better bet than Larsson to start the game but, when eventually sent on, did nothing to suggest a quick return to last season's fine form.
MF Adnan Januzaj, 4 -- Moyes has said he is the Sunderland squad member with the greatest natural talent. But he failed once again to live up to the billing.
DF Javier Manquillo, N/R -- His participation was brief and unremarkable.