At the end, after Marcus Rashford scored goals 14 and 15 of a superb season so far, all was well for Manchester United, who had made this Carabao Cup quarter-final far more attritional than they might due to Erik ten Hag shuffling his team selection. Having an eye on Saturday’s 189th derby with Manchester City meant the manager sent out a weakened XI and he watched his side burn brightly in the first half before being pushed back by Charlton, who arrived as the hopefuls from two tiers below and ended threatening to take United to penalties. This was until Rashford’s intervention: his first goal came from the service of Facundo Pellistri, a replacement making his debut, the No 10 dinking the ball over the Charlton keeper Ashley Maynard-Brewer. His second derived from a Casemiro pass, which set Rashford up for a curled finish. United could, finally, relax deep into stoppage time, after Charlton had pressed for an equaliser, Scott Fraser bouncing a free-kick at Tom Heaton. United’s stand-in keeper was excellent all evening, and gratefully gathered. This was a sixth consecutive game Rashford has scored in, and an eighth at home. “When he brings himself into position for one-on-ones in the box he will score and that is what he is doing at the moment,” said Ten Hag. “When he keeps the focus and keeps putting the same effort in he will keep on scoring.” United’s hopes of ending a six-year trophy drought remain alive and they have now enjoyed victory in 11 of their last 12 matches. Ten Hag offered a verdict on what was his 300th career win. “The performance in the first half-hour was good, especially with some young guys on the pitch – especially [Alejandro] Garnacho: he was a threat so many times,” the Dutchman said. The 18-year-old began with a burst along the left and set-up Diogo Dalot who should not have blasted over. This was followed by him again slicing through Charlton’s defence and unloading but Maynard-Brewer’s goal was not threatened. United swarmed all over their visitors, Fred hitting a pile-driver that hit Ryan Inniss’s head and knocked the defender over, so better for Charlton was Corey Blackett-Taylor’s cross that Harry Maguire turned out for a corner: when delivered by Albie Morgan it was bravely dealt with by Heaton, whose punch out came back via George Dobson’s attempt and the goalkeeper saved low down. From here, United broke, the relentless Garnacho carrying the ball 60 yards, but after Scott McTominay, Anthony Elanga, Kobbie Mainoo and Tyrell Malacia all joined in the attack it fizzled out. Ten Hag had stood down to the bench Rashford, Casemiro, Christian Eriksen, David de Gea and Luke Shaw and handed the 17-year-old Mainoo a debut, the Stockport lad operating in advanced midfield before the 9,000 Addicks enthusiasts who made the trip from London for their biggest game since the triumphant 2019 League One playoff final. What they next saw was Maguire, making a rare start, initiating the sequence that closed with Antony’s opener. The captain’s sweeping diagonal was taken by Malacia, who found Fred, and when he tapped to his fellow Brazilian, a curving 20-yard shot beat Maynard-Brewer. Charlton were showing why they are a mid-table League One side, second-best in pace, invention, attack and execution as they were pinned back, hopeful of a breakaway. But it was all United: on 33 minutes Aaron Wan-Bissaka was introduced for the injured Dalot – “a precaution”, Ten Hag said – then Fred crashed a free-kick off Maynard-Brewer’s left post, before, at the other end, Morgan, from a similar 25-yard free-kick position, missed to Heaton’s right. As the interval arrived United’s possession nudged above 70% and their shot count was nine so their slender advantage was a poor return, particularly as Heaton had to save from Fraser in added time. After the break came further Charlton resurgence via a golden chance to equalise when Lisandro Martínez and Malacia missed second balls and Fraser blazed high. At this point the ruthlessness Ten Hag has demanded previously was absent and this was further emphasised when Elanga scored from an offside position: better concentration would have allowed United’s centre-forward to hold his ground and legally finish Wan-Bissaka’s neat volleyed pass. United needed either to steady the contest or score again because those in white were no longer being cuffed aside. Ten Hag plumped for the former by bringing on Casemiro for Mainoo, Rashford for Antony, and Eriksen for Fred. By sending for the cavalry he hoped to finally put Charlton away. After a Maguire dribble – he was dispossessed – next followed Eriksen claiming a corner: the Dane hit this in and after Rashford shot, Martínez’s strike was ruled offside. Now, came Rashford’s late late show.