Manchester United were held to a third 0-0 draw in a row in all competitions as they failed to find a way past Crystal Palace on Wednesday.
There was a paucity of quality in misty conditions at Selhurst Park as Ole Gunnar Solskaer's men handed Manchester City another boost in the Premier League title race.
City's 4-1 win over Wolves on Tuesday stretched the gap at the top to 15 points, but United could not respond in kind against a Palace side who beat them 3-1 at Old Trafford in the reverse fixture.
The Red Devils failed even to have a shot between the 27th and 81st minute and have now gone three games without scoring a goal, having recently been the leading scorers in England's top flight this term.
United started scrappily but twice came close to an opening goal inside the first 20 minutes, Nemanja Matic's deflected shot brilliantly saved by Vicente Guaita before Marcus Rashford skewed a clear chance wide.
Aaron Wan-Bissaka's cross nearly provided Edinson Cavani with a tap-in, but it was mostly a lifeless first-half display from the United attack, in keeping with their previous back-to-back goalless draws.
There was little change early in the second half and Palace came close to snatching the lead through a half-volley from Andros Townsend that bounced wide.
Substitute Dan James missed the ball when presented with a free header from a Luke Shaw cross, and Mason Greenwood fired over from the edge of the box, but that was as close as the visitors came.
Patrick van Aanholt should have won the match when he was found by Luka Milivojevic, but Dean Henderson, in for the absent David de Gea, saved superbly at the feet of the left-back.
What does it mean? United being cut adrift by City
Solskjaer insisted United would not let City run away with the title, but the gap between the top two now stands at 14 points ahead of Sunday's derby.
Victory in that game would surely end any lingering United hopes of winning the trophy, and the Red Devils will need to improve significantly to get anything against Pep Guardiola's men.
Palace have an 11-point gap to the bottom three and, despite having played a game more, they are beginning to look safe.
Palace's protective Ward
Rashford and Shaw were kept discernibly quiet down the United left thanks largely to Palace right-back Joel Ward.
He made seven clearances and won back possession eight times for the home side in a diligent display, albeit one in which he was rarely stretched.
Rashford's early miss set the tone for a dreadful performance in which he offered negligible threat down the United left.
As the fog descended more thickly, Rashford seemed to fade further from the contest, which he ended with one shot, one cross and 29 completed passes.
United head to the Etihad Stadium on Sunday to meet the leaders, with Palace in action at Tottenham later that day.