Cristiano Ronaldo ended his six-game goal drought on Tuesday as Manchester United recovered from an insipid first-half display to beat 10-man Brighton 2-0 and clamber back into the Premier League top four.

The match dramatically changed complexion early in the second half, with Ronaldo scoring his first goal in 2022 before Lewis Dunk was sent off three minutes later.

But the home side still managed to make heavy weather of the situation, wasting a number of great chances to double their lead until Bruno Fernandes sealed the points deep into stoppage time.

Ralf Rangnick's team had blown half-time leads to draw 1-1 in their previous three matches in all competitions, dropping crucial points in the league and exiting the FA Cup on penalties.

In his pre-match interviews, United's interim manager had spoken about how he wanted his team to be more like Dr Jekyll and less like his literary evil alter ego Mr Hyde.

The German said after the match he had seen both sides of his team, who have struggled to find consistency and fluency under his stewardship.

"First half was Mr Hyde, second half Dr Jekyll and for a change it (the result) was different," he said. "In the end it was important to get the three points against an in-form team."

Rangnick praised 37-year-old Ronaldo, who returned to the scoresheet for the first time since December 30.

"Very important not only that he scored but it was an outstanding goal," he said. "It was important for all of us, but his overall performance was one of the best since I arrived here."

- United struggles -
Forward Anthony Elanga and midfielder Fred came into United's starting line-up for Marcus Rashford and Paul Pogba, with defender Raphael Varane also missing out due to illness.

Jadon Sancho was denied early on but the hosts created precious little as mid-table Brighton controlled the game, enjoying nearly 60 percent of possession in the first half.

David de Gea was forced to make a spectacular save to keep out a Jakub Moder header and the half-time whistle drew boos from a frustrated home crowd, with United fortunate to be level at 0-0.

The home side took the lead in the 51st minute when Scott McTominay found Ronaldo, who darted forwards, cutting past Adam Webster and firing beyond goalkeeper Robert Sanchez from the edge of the box.

It was the Portugal's forward's 15th goal since he returned to United from Juventus in August.

Things got dramatically better for United minutes later as Elanga's pace caught out Dunk, who brought down the teenager.

Referee Peter Bankes showed a yellow card to the Brighton captain, only to change it to red after reviewing the foul on the advice of the video assistant referee.

United were now on top but they failed to kill off the game despite their man advantage.

They almost paid for their profligacy when Moder beat De Gea but he saw his shot cannon back off the crossbar in the 78th minute and ex-United player Danny Welbeck flashed a late header high as the home fans breathed a sigh of relief.

United wrapped up the victory in the 97th minute when substitute Pogba took a quick free-kick and Fernandes collected the ball inside his own half and raced forward before firing home.

The three points lift United into the fourth Champions League qualification spot, two points ahead of West Ham and four behind third-placed Chelsea, who have a game in hand.

Arsenal, Wolves and Tottenham are also within striking distance of the top four and all have games in hand.