Brazilian midfielder Casemiro scored two goals for the team, dinking the ball over the goalkeeper in the 54th minute and then extending the lead with a low shot four minutes later.
Fred also scored, making it 3-0. Reading's former Liverpool striker, Andy Carroll, was sent off with a second yellow card. Reading scored a consolation goal through Amadou Salif Mbengue, but it was not enough to secure a win.
Marcus Rashford had thought he had become the first player to score in 10 consecutive home matches for United, but his effort was ruled out for offside by VAR. Just before the interval, Reading almost took the lead when Junior Hoilett had a great chance, but his close-range shot was well saved by David de Gea.
The game was held at Old Trafford and Reading, managed by former title-winning United midfielder Paul Ince, put up a good fight. Despite being outnumbered, they held on until Casemiro scored the first goal. The Brazilian's goal-scoring prowess was on full display as he extended the lead with a well-placed shot.
Fred's goal put the game out of reach for Reading and they were unable to mount a comeback, even after Andy Carroll was sent off. The consolation goal from Amadou Salif Mbengue was too little too late, and Manchester United secured their place in the fifth round of the FA Cup.
In conclusion, Manchester United's win was a solid performance, and Casemiro's two goals were the highlights of the game. Despite a few close calls, Reading were unable to secure a win, and Manchester United will continue their FA Cup journey in the next round.