The Mancunian side went into the break with a two goal lead. Ten Hag's side managed to break the deadlock through McTominay before Harry Maguire extended his side's lead before the half-time.
United lowered the intensity and conceded twice in just nine minutes through Simms and Wan Bissaka's own goal.
The Championship side forced the Red Devils to defend tooth and nail and finally got the reward they were looking for when Binks' shot was blocked by Wan-Bissaka's arm inside the box. Robert Jones pointed to the spot and Haji Wright repeated his heroics against Watford by sending Onana the wrong way.
The game went to extra time and it looked like Coventry City had wrapped up a last-gasp victory when Torp beat Onana, but his goal was disallowed for offside. Finally, Hojlund scored the winning penalty in the shootout to send the Red Devils into the final.