Tottenham skipper Cristian Romero was accused of letting his team-mates down after his first-half red card helped condemn his side to defeat as Manchester United extended their winning run under Michael Carrick.

Bryan Mbeumo put United in front after 38 minutes at Old Trafford when he applied a brilliant finish to a superb corner routine involving Bruno Fernandes and Kobbie Mainoo.

Fernandes wrapped up the win late on as he turned home Diogo Dalot's inswinging cross.

But the main focus was on Romero. So critical of Tottenham's board in midweek, the Argentine gave referee Michael Oliver no option other than to brandish a red card with a tackle that caught Casemiro just above the ankle and left the Brazilian screaming in pain.

It was Romero's second red card of the season, which means he will miss four games, including the north London derby against Arsenal on 22 February.

BBC Match of the Day pundit Danny Murphy said Romero had "let his team-mates down".

The result means Tottenham have now gone seven Premier League games without a win, a run that has yielded just four points and leaves them 14th and too close to the relegation places for comfort.

Although they were not at their best, United at least avoided the same embarrassment they suffered against an Everton side reduced to 10 men even earlier in the game in November, when David Moyes' side claimed victory.

The result led to more chants backing interim manager Carrick as United consolidated their position in the top four.

With each passing game, Ruben Amorim's decision to condemn Mainoo to the substitutes bench for the entire Premier League season looks more ridiculous.

Amorim's reasoning was Mainoo had to compete for a starting spot with Fernandes as, effectively, they couldn't play together.

The evidence suggests otherwise.

A pre-planned corner routine involved Mainoo coming short to take Fernandes' pass down the goalline. The England midfielder flicked the ball towards the edge of the penalty area with a single touch. Mbeumo only needed one to find the bottom corner in a crowded penalty area.

It was simple – but brilliant. The kind of move United were incapable of executing under Amorim.

Fernandes put a flourish on the outcome when he arrived at the far post to finish off Dalot's dangerous cross.

Showing he has a knowledge of the club understandably far deeper than that of Amorim, Carrick marked the 68th anniversary of the Munich air disaster that destroyed Matt Busby's famous 'Babes' by giving a late debut to 18-year-old Tyler Fletcher - son of former midfielder Darren and twin brother of Jack.

Amorim never won four games in a row as United manager. Carrick has managed it in the space of four games, including matches against three of the biggest teams in the country. The songs at the end in his honour are yet another sign the fans are very happy with the job he has done so far.

Tottenham manager Thomas Frank spent the build-up to this game talking about his captain's latest damning social media post, in which he accused the club's hierarchy of not providing the squad with enough backing and leaving it ill-equipped to deal with the strains of a campaign that includes a tilt at the Champions League.

He will spend the aftermath of the game talking about Romero, too.

The days are long gone when a player can go for the ball knowing you will take the man as well.

Even if Romero had made contact with the ball, it would not have stopped him catching Casemiro in a dangerous way, which was certain to trigger a red card. It will be the 15 March encounter with Liverpool before he plays again.

His first sending off this season came against Liverpool in December but the reality is Tottenham's captain has also escaped sanction for two other red-card tackles in different matches against Brentford, according to the Premier League's key match incident panel.

It is bound to raise questions over Romero's captaincy at a time when Spurs are so short on numbers. In addition to four matches without Romero, full-back Destiny Udogie also looks set for a spell on the sidelines after limping off with an injury 10 minutes into the second half.

Manchester United's next game is in the Premier League on Tuesday at West Ham (20:15 GMT). Tottenham play on the same evening, at home to Newcastle (19:30).