Arsenal supporters had almost forgotten what it was like to win without their nerves being shredded. They were reacquainted with the feeling on an occasion when everything felt right from the start and got better and better. It was all over by half-time, Arsenal three goals to the good and the Emirates Stadium purring over a virtuoso Bukayo Saka performance. The England winger had not been himself before he was forced to take time out at the end of March to rest an achilles problem – and one or two others aches. He was back in the starting XI here and the bang he produced could be heard in Manchester. City do not play until Monday night. They will kick off at Everton six points behind Arsenal at the top, albeit having played two games fewer. Arsenal have turned up the heat inexorably. It looked as though Saka was immune to the pressure on his club, which has been such a feature of the season and the last few months, especially. When did Arsenal last win in the league with a degree of comfort?…