Mauricio Pochettino has been leaning on the data, using it as proof that his side’s performances have been better than their results suggest, but even he knows that it is easier to make the numbers look good when Chelsea accompany the promise between the boxes with substance at both ends of the pitch. This was an improvement from Chelsea, who moved into the fourth round of the Carabao Cup after a clinical finish from Nicolas Jackson. They stayed firm after initially being outplayed by Brighton and took advantage when Jackson made up for his foolish spate of bookings. So careless-in-front-of-goal Chelsea could celebrate the rarity of getting one over Roberto De Zerbi’s side, who regretted not making more of their early dominance. De Zerbi was not entirely pleased with Brighton’s display, though. Kaoru Mitoma was having a quiet evening against Marc Cucurella, filling in at right-back against his old side, and there were flashes of intent from Chelsea. As ever, though, the question was whether there would be any cohesion. Jackson was jeered by the away end after twice running the ball out for goal-kicks and Mykhailo Mudryk remained inconsistent on the left, occasionally troubling Tariq Lamptey with his speed but mostly causing frustration with his habit of running down dead ends. Yet Chelsea were slightly on top as half-time approached. Caicedo was in an engaging battle in midfield against Carlos Baleba, the player who replaced him at Brighton. Mudryk kept going and might have had a penalty had he gone to ground after a risky challenge from Igor Julio. Cole Palmer turned a shot wide at the near post. Brighton, who replaced Fati with Solly March at half-time, had lost their flow. Mahmoud Dahoud threatened at the start of the second half, Lesley Ugochukwu blocking the midfielder’s shot, but the loose balls were beginning to go Chelsea’s way. Ugochukwu, strong and disciplined in defensive midfield, became increasingly authoritative as Brighton found themselves sinking deeper. Chelsea were playing with more urgency, pressing harder, and earned their reward after 50 minutes. Jan Paul van Hecke was hurried into an error and Brighton’s balance disappeared when the ball reached Ian Maatsen on the right. An overload had developed and Palmer took over. He took his time, rolling a foot over the ball before slipping it through for Jackson to sweep a low finish beyond Bart Verbruggen. There was no overthinking from Jackson, who had infuriated Pochettino by getting himself banned for Monday’s trip to Fulham. The striker took the shot first time, sliding it into the net, and the 22-year-old felt the frustration pouring out of him after scoring for the first time in over a month. Soon he was through again; this time, though, Verbruggen denied him. The tie hung in the balance and Brighton stirred. They should have equalised when a cross reached March but his header was too close to Sánchez. Chelsea’s nerves grew and Pedro volleyed over in added time.