Cristiano Ronaldo surpassed 800 career goals as Manchester United got back to winning ways in the Premier League with a 3-2 success over Arsenal at Old Trafford.
Arsenal took the lead in bizarre circumstances when Emile Smith Rowe volleyed home with David de Gea down injured after Fred stepped on his ankle, but Bruno Fernandes restored parity on his 100th United appearance.
Ronaldo marked his return to the starting line-up with a milestone goal to put the Red Devils in front, with newly appointed head coach Ralf Rangnick – who had been waiting on visa clearance before taking charge of first-team affairs – standing to applaud in the stands.
Martin Odegaard hit back in rapid time for the Gunners but his foul on Fred enabled Ronaldo to rattle in a ferocious penalty to end United's three-game winless run in the top flight and secure just their second victory in nine.
Arsenal opened the scoring in a controversial fashion in the 13th minute, with Smith Rowe volleying home from 20 yards after spotting that De Gea was prone after a collision with Fred. Referee Martin Atkinson appeared to have awarded United a free-kick but following a VAR review, the goal was allowed to stand.
Fred helped get United back on level terms before half-time by cutting the ball back for Fernandes to steer an effort beyond Aaron Ramsdale, though Harry Maguire was perhaps lucky not to give away a penalty following a tussle with Takehiro Tomiyasu in the box.
Ronaldo put United in front with his landmark goal in the 52nd minute, holding his run to emphatically sweep home a pass from Rashford.
However, Arsenal were level two minutes later when Odegaard guided Gabriel Martinelli's cutback into the bottom-left corner.
Odegaard's lunge on Fred resulted in a penalty after the referee visited the pitchside monitor and Ronaldo fired it straight down the middle to seal an important win for United.
What does it mean? Ronaldo is back with a bang
Michael Carrick dropped Ronaldo to the bench for his first league game as caretaker boss against Chelsea at the weekend.
The appointment of Rangnick, who favors the high press, led to further questions over Ronaldo's suitability for this United team, but he proved he can deliver the goods against Arsenal.
He reached 801 goals across his illustrious career, with his double taking his total for United to 130. The 36-year-old has also registered 450 for Real Madrid, 115 for Portugal, 101 for Juventus, and five for Sporting CP.
Fernandes was overshadowed by Ronaldo on his landmark appearance, but the midfielder was once again hugely important for United. In his 100 appearances for the club, he has been directly involved in 79 goals (45 scored, 34 assisted) – more than any other player for a Premier League side since his debut.
Stopping the rot
Although Smith Rowe's opener meant United had conceded nine straight goals at Old Trafford without reply for the first time in the Premier League era, they avoided succumbing to an unprecedented seven-game winless streak against the Gunners in the league.
United entertain Crystal Palace at Old Trafford on Sunday, while Arsenal have an extra day of rest before their trip to Everton.