Manchester City will take on Tottenham in April’s Wembley showpiece aiming to win the Carabao Cup for a remarkable fourth consecutive year, a feat only Liverpool have achieved. For Ole Gunnar Solskjær and Manchester United this was a fourth successive semi-final reverse: losing at the stage is becoming a habit they have to break. What killed them were the two latest episodes of slack defending from set-pieces. Each presaged John Stones and Fernandinho’s strikes. Here, too, is another bad practice that the manager bemoaned afterwards but the simple fact is that it is on him to eradicate. City are jubilant and rightly so. When it mattered they landed the knockout punches to set up a fascinating tactical showdown between Pep Guardiola and José Mourinho. As the resurgent Stones said: “We tried to be more clinical in the final third and did the job at the end of the day.” Each manager made two changes. Solskjær selected Dean Henderson to continue in goal in the competition, meaning David de Gea was on the bench and Victor Lindelöf replaced Eric Bailly in central defence. Guardiola dropped Rodri and with Bernardo Silva suspended, Fernandinho and Riyad Mahrez came into a City XI with no recognised No 9, Sergio Agüero and Gabriel Jesus among the substitutes. City began how they like: pinging possession around as Phil Foden, Oleksandr Zinchenko, Fernandinho and Stones all took turns. They had the ball in the net when Ilkay Gündogan turned home Foden’s cross from the left but it was correctly ruled out for offside. The contest had a far higher tempo than last month’s cagey 0-0 draw here. Then Guardiola oversaw an approach that was muted for him and his team. What did still remain, though, was City’s penchant for sloppiness from the back as Stones’ errant pass caused Raheem Sterling to lose the ball, Scott McTominay passed to Bruno Fernandes and the City goalkeeper Zack Steffen flung himself high and left to tip the Portuguese’s goal-bound shot out for a corner. An invigorating spectacle was next decorated by Kevin De Bruyne who, when the ball was rolled to him in a central area, paused, then let fly: the effort left Henderson a spectator, the ball smacking back off his right-hand post. Guardiola had João Cancelo roving in from right-back to make an extra man in midfield, a ploy he uses occasionally, yet it did not seem to confuse United: Paul Pogba often following from his wide left berth and pickpocketing him when he could. United were functioning on around 30% possession only. After Foden had a second City strike chalked off for offside - the third in the half with Marcus Rashford’s effort being disallowed early in the game - the home side showed the menace they possessed: Rúben Dias’s block from Rashford was desperate and effective. Rashford’s next contribution was a touch that disappointed when Fred’s chip had the forward bearing down on Steffen’s goal: the ball slipped from his boot and the keeper collected. What had developed was a contest akin to a boxing match in which each pugilist took turns to aim at the other. Nothing was quite connecting but the sense was it might at any moment. By the interval the sides had become a touch becalmed, much of the action occurring in the middle third, each feinting and hoping for an opening that would prove decisive. United’s start to the second half consisted of a Luke Shaw free-kick that was scrambled clear. City’s opening offensive act was Fernandinho’s foul on Pogba that brought a trademark yellow card for the captain. Brighter from the visitors was how Sterling’s wriggle drew McTominay into conceding a free-kick from which they struck. Foden curled a cute delivery into a crowd of players, a hapless Harry Maguire watched the ball pass, and the delighted Stones bundled in. How might United respond to the threat of another semi-final defeat under Solskjær? A balance had to be found between pressing for an equaliser and not allowing City in to score a second that might be fatal. A warning came when City broke and Sterling forced Henderson to concede a corner. Another had Sterling this time being stymied by Henderson low down. Henderson’s third vital intervention was to palm Riyad Mahrez’s 20-yard shot over. United emerged from this mini-siege to claim a corner and Maguire headed over. A further flicker of hope came from a Fernandes attempt that went straight at Steffen. Fernandinho’s clinching strike came when a weak Aaron Wan-Bissaka header from a City corner reached him and he beat Henderson from outside the area. By the close Guardiola’s side deserved victory. For Solskjær’s team it is that sinking feeling again.