Celtic flexed their muscles at St Johnstone to ensure their nine-point lead over Rangers at the top of the Premiership remained intact. The chasing Light Blues beat Ross County 2-1 at Ibrox on Saturday, but the champions handled the pressure well at McDiarmid Park, recording a convincing 4-1 win. The home defender Andrew Considine turned a Kyogo Furuhashi cross into his own net in the 13th minute and the Japan striker notched himself midway through the first half. Drey Wright pulled a goal back for St Johnstone three minutes later. Aaron Mooy restored Celtic’s two-goal lead in the 38th minute with Considine – appearing in his 600th club game – sent off by the referee, David Dickinson, in added time for a pull on Oh Hyeon-gyu, with fellow substitute David Turnbull adding the fourth from the resulting free-kick. Ange Postecoglou’s side have lost once in 25 league games this season and once again looked a formidable outfit. St Johnstone’s 2-0 midweek win at Motherwell was their first victory in eight games but little was expected against the visitors. James Brown, Tony Gallacher, Graham Carey and Connor McLennan came into the home side’s lineup while Postecoglou made just one change, Mooy replacing Matt O’Riley in midfield. The home side battled hard to get an early foothold in the game but the Hoops slowly gained control and took take the lead when Furuhashi raced on to a pass from Mooy. From the byline, his attempted ball towards fellow Japanese teammates Daizen Maeda and Reo Hatate was turned into his own net from close range by the helpless Considine. The early blow to the belief of the Perth side was compounded in the 22nd minute when Furuhashi fired high past Remi Matthews following a long pass from Mooy – who was having a fine game – and a cross from Jota. It looked like being another romp for the champions but shortly afterwards they switched off for a moment and Wright drove past Joe Hart from 20 yards to give the home side some hope. However, the visitors remained calm and Jota’s clever chip over the St Johnstone defence gave Mooy time and space to calmly lob Matthews from 16 yards and when Considine was sent packing for his foul on Oh just outside the box, Turnbull took a short O’Riley pass and fired past Matthews, with the goal confirmed after a long VAR check for offside.