Michael Carrick’s position as Manchester United manager was jeopardized further after a 2-0 loss at Chelsea in the Premier League, with Lisandro Martinez’s reckless sending-off adding to the woes of the beleaguered English giant on Saturday.

It was a bad day for the other Manchester club, too, when first-placed City fell at home to Brighton 1-0 for a second straight league loss after opening the campaign with seven wins in a row.

Carrick was already under huge pressure — and seemingly operating on a match-by-match basis — heading into the game at Stamford Bridge, for which he restored Bruno Fernandes to the starting lineup after dropping the captain last week.

It has gotten worse for Carrick, with United now on a nine-match winless run in all competitions — its longest streak without a victory since 1988, according to the BBC — after second-half goals by 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 awarded 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 in the spotlight for criticizing United’s hierarchy recently, was given a second yellow card in a four-minute span.

As Martinez walked off the field and down the tunnel, Carrick didn’t even acknowledge the player.

“It has a major importance on the game,” Carrick said of the red card. “A huge moment.”

United plunging toward relegation zone

United stayed on just one win in the league after nine games and is one point above the relegation zone. There’s a chance the 20-time English champion could be in the bottom three by the end of the round, a desperate situation for a club widely regarded as the biggest in the country.

United’s only two victories from 13 matches in all competitions this season were against promoted Ipswich in the Premier League and tournament newcomer Sabah in the Champions League.

United’s next match is at home to Roma in the Champions League on Tuesday and there has to be some doubt whether Carrick will still be in charge.

“I think the mentality was there right from the first minute,” United forward Bryan Mbeumo said. “We still trust everyone.

“Maybe today we just missed some chances. We could have been up early in the game, but that’s a positive to take out of this game.”

Haaland scoring run ends in City loss

Man City striker Erling Haaland had scored in his previous seven league games — leaving him four off Leicester great Jamie Vardy’s record of netting in consecutive matches — but that run ended against Brighton in a rematch after their English League Cup meeting on Wednesday, won by City on penalties.

Yasin Ayari, one of the Brighton players to miss the team’s shootout loss, made amends with an 11th-minute winner at Etihad Stadium.

With City also losing at Aston Villa 2-1 last weekend, Arsenal — which is tied on points in second place — can move into first with a win or a draw at Liverpool on Sunday.

“We were aware that we weren’t going to win all the games,” City manager Enzo Maresca said. He was the first ever manager to win his first seven Premier League games in charge of a club. “So this kind of moment has arrived ... we need to move on and win games as soon as possible.”

City’s future continues to be shrouded in doubt after the club was found guilty of large-scale financial rule-breaking in an explosive verdict last month. City is awaiting a sanction, having also lodged an appeal.

Brighton, one of the league’s surprise packages this season, moved into third place — two points off the lead.

Bournemouth wins again

Another win and another clean sheet for in-form Bournemouth.

By beating Leeds 2-0 thanks to goals by Evanilson and Amine Adli, Bournemouth made it six straight victories in all competitions without conceding a single goal and moved up to seventh place.

Sunderland stayed in last place after losing at Coventry 3-1, next-to-last Nottingham Forest lost at Brentford 2-0, while promoted teams Hull and Ipswich drew 2-2.

Later, Tottenham hosted Crystal Palace, and Fulham visited Aston Villa.