Sunderland's home woes plunged to record depths as George Saville's free-kicks twice exposed goalkeeper Robbin Ruiter and earned Millwall a 2-2 draw on Sunday (AEDT).
The news was better for Wolverhampton Wanderers as it returned to the EFL Championship summit with a well-earned win at Reading, while Aston Villa also impressed on the road in edging out Queens Park Rangers.
At the bottom, Birmingham City celebrated a much-needed three points over mid-table Nottingham Forest.
But it was Sunderland that gave incoming manager Chris Coleman a taste of the challenge he faces as it became the first team in English football history to go 20 competitive home matches without a win.
Coleman, who left his job as Wales boss on Friday, is expected to be appointed at the Black Cats as early as Monday.
His first task will be to address the side's goalkeeping situation after Ruiter, who recently replaced the dropped Jason Steele, committed a pair of howlers in the four-goal draw with Millwall, letting two saveable Saville free-kicks through his grasp.
To the Dutchman's relief, his errors were matched at the other end by Jordan Archer's own failure to deal with two innocuous deliveries from wide areas.
Wolves secured an impressive 2-0 win away at Reading to restore their two-point lead at the top of the table.
Sheffield United temporarily held the position after its win over Burton Albion on Saturday (AEDT), but Nuno Espirito Santo's side provided the perfect response with an accomplished display at Madejski Stadium.
Ivan Cavaleiro notched the opener with a tidy finish in the 16th minute before Matt Doherty completed a third consecutive victory late in proceedings.
Elsewhere in the top six, Cardiff City comfortably accounted for Brentford 2-0 while fourth-placed Bristol City slipped off the pace in a 0-0 draw at Sheffield Wednesday.
Albert Adomah bagged a brace to inspire Aston Villa to a come-from-behind 2-1 victory against QPR at Loftus Road.
The Ghana winger scored from the spot on the stroke of half-time to cancel out Jamie Mackie's close-range opener.
He continued his star turn just prior to the hour, firing a superb low shot into the bottom far corner to seal an ideal follow-up to last weekend's home defeat against Wednesday.
The victory moved Villa three points clear of Middlesbrough, which visits Leeds United on Monday (AEDT), while QPR sits 15th.
Meanwhile, Che Adams scored the only goal as Birmingham climbed out of the bottom three with a narrow 1-0 defeat of Forest.
The 21-year-old's fifth-minute strike proved enough for the hosts to end a four-match winless run.
Steve Cotterill's side is now two points clear of 22nd-placed Burton ahead of tough trips to Middlesbrough and Sheffield United.
Forest, meantime, is still within a game of the top six and is yet to draw any of its 17 league matches this term.