An inventive set-piece allowed Tom Rogic to net the only goal in a 1-0 win against Motherwell as Celtic came through their first test without a recognised striker.
Rogic converted David Turnbull’s disguised delivery at the end of an end-to-end first half during which Motherwell hit the bar.
The home side were far more comfortable after the break as they restored a four-point deficit on Rangers but they suffered another injury to an attacking player when James Forrest trudged off with a muscle problem.
Celtic were without a centre-forward in their 18-man squad after midweek hamstring injuries to Albian Ajeti and Kyogo Furuhashi, although the latter’s problem was described pre-match by Ange Postecoglou as “not significant”.
Turnbull started up front, supported by Rogic and Callum McGregor behind him.
Motherwell also had fitness issues in a key area with Bevis Mugabi their only natural centre-back. Left-back Jake Carroll lined up in the middle of defence.
The visitors started with three strikers and gave as good as they got in the first half, although Forrest had an excellent early chance when he stabbed wide after McGregor’s return pass.
Rogic had a shot well blocked but Motherwell twice came close through Callum Slattery, who glanced a header wide before striking the bar from 22 yards.
Mikey Johnston replaced Forrest in the 18th minute as Motherwell continued to press. Kaiyne Woolery had a shot blocked before Tony Watt shot across the face of goal.
The Celtic ultras’ silent protest against the planned appointment of Police Scotland’s Bernard Higgins to the Parkhead staff was broken elsewhere in the stadium as supporters realised their team were up against it.
Motherwell’s pressure continued and Joe Hart made an excellent stop from Sean Goss after a long throw.
Celtic improved around the half-hour mark. Johnston hit a couple of efforts wide, Liel Abada shot straight at Liam Kelly and Turnbull hit a deflected effort which the Motherwell goalkeeper pushed over after readjusting his body.
Motherwell were still committing men forward and they were caught out by a long ball but Turnbull made a mess of his attempt to chip Kelly with the outside of his boot.
The breakthrough came when Slattery was penalised for attempting to stand his ground as Rogic competed for a high ball just on the left side of the box. Turnbull rolled the free-kick across the 18-yard box and the Australia midfielder peeled off untracked and fired into the top corner.
Turnbull set up Rogic again seconds after the interval but Nathan McGinley slid in to deny the goalscorer.
Celtic were now in full control. Turnbull and Rogic threatened from the edge of the box and Kelly saved well from Johnston’s header.
Motherwell looked like they had spent all their energy in the opening period, although Connor Shields headed wide from a decent chance seconds after coming on.
Johnston went off for fellow substitute Anthony Ralston before Rogic missed a couple of chances to ensure a few nervy moments for Postecoglou late on, although nothing of major significance.