Middlesbrough's push for promotion from the Sky Bet Championship stuttered as Rotherham beat them 1-0 to do their own survival hopes the world of good.
Boro, who had won three of their last four games, wasted a plethora of chances in the first half and were left to rue them as Millers midfielder Lee Frecklington scored an unlikely winner two minutes from time.
The fact that Neil Warnock's side were even on level terms at that point will leave Boro boss Aitor Karanka scathing as his side squandered chance after chance in the first half, with David Nugent and Gaston Ramirez the guilty parties.
Warnock will not be too bothered about that, though, as the victory was Rotherham's third in a row and leaves them just a point off the drop zone having held on for the final few minutes with 10 men after Greg Halford was dismissed.
After a cagey opening it was Boro who should have taken the lead in the 16th minute, but Nugent's wayward finishing let the hosts off.
The former England international robbed Richard Wood and raced through on goal only to blaze over with just Lee Camp to beat.
Karanka's men came even closer to scoring just three minutes later when the woodwork saved the Millers as Ramirez whipped a curling 25-yard free-kick over the wall and into the inside of the post.
Still the Boro attacks kept coming and Ramirez was again close as he whistled a dipping volley just wide before Nugent again missed target with a free header from Albert Adomah's inviting cross.
Somehow, the Millers found themselves on level terms at half-time and they were able to make a better fist of it after the restart, causing Boro problems from set-pieces, which saw Halford and Kirk Broadfoot have headed opportunities that they could have done better with.
Frecklington skied a decent chance from just inside the area as Warnock's men pushed for an unlikely opener.
Boro were a shell of the side that marauded through the United defence at will in the first half and they had to wait until the 83rd minute to create a decent opening as Ramirez fired over after good work from Stewart Downing.
But any ideas Boro had of a late onslaught in search of a winner were quickly extinguished as Rotherham stole an 88th-minute lead.
Jonson Clarke-Harris made headway down the left and cut the ball back to Frecklington who slammed the ball into the roof of the net from eight yards.
Rotherham's path to victory was not going to be easy as Halford was dismissed for second yellow card immediately after kick-off and a nervy period ensued as Boro threw everything forward.
But the Millers put their bodies on the line, superbly blocking Adomah's late effort as they held on for another coupon-busting win, just three days after a 1-0 success at Sheffield Wednesday.