Celtic hammered Hibernian 4-1 after Oh Hyeon-gyu's double inspired victory for the Scottish Premiership leaders.The forward helped the Hoops to a comfortable win at Celtic Park and ensured they remain eight points clear at the top of the table, with Rangers also beating Hearts 1-0.Oh opened the scoring after just five minutes before Matt O’Riley doubled the lead nine minutes before the break.Luis Palma’s penalty after 51 minutes put Celtic further in control before Oh added a fourth soon after.Christian Doidge grabbed a consolation for Hibs who remain fifth, two points off the top four.Abdallah Sima’s first-half strike gave Rangers a narrow win at Hearts when he latched on to a James Tavernier delivery to beat Zander Clark.David Watson scored a late winner for Kilmarnock as they won 1-0 at Aberdeen and climbed to sixth.Chris Kane’s dramatic injury-time winner gave St Johnstone a 1-0 victory over St Mirren to lift them out of the bottom two.The substitute netted after his penalty was initially saved by Zach Hemming following Charles Dunne’s foul on Liam Gordon in the box.