Michael Carrick's position as Manchester United manager came under further pressure after a 2-0 loss at Chelsea in the Premier League, with Lisandro Martinez's reckless sending-off adding to the club's problems Saturday.
It was also a bad day for Manchester City, which lost 1-0 at home to Brighton for a second straight league defeat after opening the season with seven consecutive wins.
Carrick was already under heavy pressure and seemingly operating on a match-by-match basis heading into the game at Stamford Bridge, where he restored Bruno Fernandes to the starting lineup after dropping the captain last week.
United's situation worsened as its winless run in all competitions stretched to nine matches -- its longest such streak since 1988, according to the BBC -- after second-half goals from Morgan Rogers and Cole Palmer.
"Things have gone against us, and gone against us in a big way," Carrick said. "It unraveled quickly."
Palmer converted a 64th-minute penalty after Martinez jumped with a raised elbow toward Wesley Fofana at a corner and struck the Chelsea defender in the face.
A video review confirmed the offense, and the Argentina defender, already under scrutiny after criticizing United's hierarchy, received his second yellow card in four minutes.
As Martinez walked off the field and down the tunnel, Carrick did not acknowledge him.
"It has a major importance on the game," Carrick said of the red card. "A huge moment."
United remained on just one league win after nine games and sat one point and one place above the relegation zone.
With its next two league matches against Aston Villa and Liverpool, the 20-time English champion could soon find itself in the bottom three.
United's only two victories in 13 matches in all competitions this season came against promoted Ipswich in the Premier League and tournament newcomer Sabah in the Champions League.
United next hosts Roma in the Champions League on Tuesday, and Carrick said he expected to remain in charge.
"I'm just looking forward to getting the boys ready for midweek," he said.
"I thought it was as good as we'd played for some time in the first half. We looked dangerous, we looked fluid, we looked like a good team."
Other matches
Manchester City striker Erling Haaland had scored in his previous seven league matches, leaving him four short of Jamie Vardy's record for consecutive games with a goal, but that streak ended against Brighton.
Yasin Ayari, one of the Brighton players who missed in the team's English League Cup shootout loss to City on Wednesday, scored the winner in the 11th minute at Etihad Stadium.
With City also losing 2-1 at Aston Villa last weekend, Arsenal, tied on points in second place, can move into first with a win or draw at Liverpool on Sunday.
"We were aware that we weren't going to win all the games," City manager Enzo Maresca said. "So this kind of moment has arrived ... we need to move on and win games as soon as possible."
Brighton moved into third place, two points off the lead, and has now beaten Arsenal and City without conceding.
Bournemouth continued its strong form with a 2-0 win over Leeds on goals from Evanilson and Amine Adli. The victory was Bournemouth's sixth straight in all competitions without conceding and lifted the club to seventh.
Tottenham moved one place below Bournemouth on the same number of points after beating 10-man Crystal Palace 2-0 for a third consecutive victory.
Aston Villa squandered a lead in a 1-1 draw with Fulham after goalkeeper Zion Suzuki dropped an inswinging corner over his own goal line. Nicolas Jackson had put Villa ahead.
Sunderland remained in last place after losing 3-1 at Coventry, next-to-last Nottingham Forest lost 2-0 at Brentford, and promoted Hull and Ipswich drew 2-2. (AP)
