Tyrone Mings took advantage of Manchester United's sloppy defending to score his first Premier League goal as Aston Villa came from behind in a 2-2 draw at Old Trafford.
United had to chase the game after the impressive Jack Grealish opened the scoring 11 minutes into an error-strewn contest that saw the host equalise through a Tom Heaton own goal and then go ahead when Victor Lindelof scored for the first time this season.
Any hopes Ole Gunnar Solskjaer had of seeing his side protect the lead were dashed within two minutes as the unmarked Mings volleyed home an equaliser from close range to help Villa claim a share of the points its performance deserved.
The result leaves United with one win from their last four domestic outings and, with Tottenham arriving in midweek before the Manchester derby against City on Saturday, Solskjaer must address problems in a defence that has not kept a clean sheet in nine league games.
United started brightly, winning midfield battles and launching swift attacks through Juan Mata, but it was caught on the counter 11 minutes in.
Anwar El Ghazi's cross from the Villa right floated beyond United's defenders and landed at the feet of Grealish, who cut inside Andreas Pereira before launching a shot that curled over the rooted David de Gea and found the top corner of the net.
But United was let off the hook for a poor first-half performance when Marcus Rashford found space in the box as Pereira hung a tantalising cross at the far post and the England forward's header bounced in off Heaton's arm.
United increased the tempo after the interval and it had the wind in their sails when Fred's cross was flicked to the far post by Villa striker Wesley for Lindelof to send a header back across Heaton's goal and into the far corner of the net.
But nobody marked Mings as Villa poured forward and the England defender - played onside by Brandon Williams - connected with Matt Targett's chipped ball into the box, lashing home a low volley that beat De Gea for power.
Solskjaer sent on Jesse Lingard and Mason Greenwood to try and force a winner but Dean Smith's men held firm, with Heaton saving from Fred before the final whistle.
What does it mean? Solskjaer on thin ice
United's results are forcing its board to contemplate the reality of a finish outside the top half of the Premier League and, with bosses dropping like flies at rival clubs, Solskjaer likely needs December victories to save his job.
Grealish's swagger serves Villa well
The confidence with which Grealish set about finding holes in the United defence seemed to fill his team-mates with the belief that they could get a result and while comparisons with Eric Cantona might be kind on the Birmingham-born playmaker, his goal was reminiscent of the Frenchman in his pomp.
Pereira's cross fails to paper over cracks
There is no denying the quality of the cross Pereira delivered to tee up United's equaliser but the Brazilian was otherwise ineffective, providing neither grit nor guile and giving Grealish an easy ride.
United has a tough week ahead, with games against Tottenham at home in midweek and Manchester City away on Saturday, while Villa travels to Chelsea on Wednesday before entertaining Leicester City on Sunday.