Celtic held their narrow lead over Kilmarnock to restore their four point lead at the top of the Scottish Premiership.
The Hoops secured back-to-back wins after the Europa League win over Besiktas in midweek thanks to Liam Scales goal.
Kasper Hogh thought he had opened the scoring before VAR stepped in to flag a foul in the build-up by Mika Baur. But Celtic wouldn’t have to wait much longer as Scales bundled the ball into the net.
Benjamin Nygren had the chance to double the advantage from the penalty spot, after Aaron Tshibola was penalised for a handball in the box following a VAR check.
However, goalkeeper Nico Mantl guessed right and denied the Swede the goal – with rock bottom Kilmarnock passing up chances in the closing stages.
But Martin O’Neill now takes his side into the international break with a lead over their rivals Rangers – who had cut the gap at the summit on Saturday.
Celtic: Johnstone, Donovan, Carter-Vickers, Scales, Tierney, McGregor, Baur, Nygren, Jota, Hogh, Duran Subs: Sinisalo, Yang, McCowan, Tounekti, Osmand, Oxlade-Chamberlain, Murray, Forrest, Ralston.
Kilmarnock: Mantl, Brandon, Stanger, McCarthy, Sckjonning-Larsen, Owen, Tshibola, Lowery, Kiltie, John-Jules, Hugill Subs: Ferrie, Kamson-Kamara, McKenzie, Deas, Ring, Meers, Clescenco, Daniels, Rice.