David Turnbull won and converted a penalty to send Celtic on their way to a 3-0 victory over Dundee.
Celtic goalkeeper Joe Hart made the best save of a goalless first half, but the cinch Premiership champions were three ahead by the midway point of the second.
Turnbull beat former Motherwell team-mate Trevor Carson from the spot in the 51st minute after getting a foul from Grant Irvine as he held off a challenge from Ryan Howley on the edge of the box.
The referee initially awarded a free-kick, but VAR official Steven Kirkland upgraded the award to a penalty and Turnbull converted down the middle.
Kyogo Furuhashi doubled the lead in the 63rd minute, despite heading down the tunnel during the first half for treatment to a recurring shoulder injury. The Japanese striker made an untracked run to meet Callum McGregor’s cross and head home from 12 yards.
Furuhashi turned provider four minutes later as he ran on to Alistair Johnston’s pass to cut the ball back for Matt O’Riley to side-foot home.
Celtic handed debuts to Nat Phillips, Luis Palma and Paulo Bernardo, while Reo Hatate made a comeback from injury off the bench.
Brendan Rodgers was able to give each of his goalscorers an early finish, with Tuesday’s Champions League opener against Feyenoord in Rotterdam in mind.
Phillips started ahead of Gustaf Lagerbielke as Celtic struggled to create space to get in behind Dundee for much of the first half.
Daizen Maeda had a shot stopped after an intricate one-two with Greg Taylor and later saw a goal ruled out for offside after running on to Liam Scales’ lofted pass.
O’Riley saw a deflected effort hit a post, while Yang Hyun-jun looked lively on the right wing after coming in for Liel Abada, who suffered a thigh injury on international duty which is set to rule him out for several months.
The South Korean winger hit a shot wide of the near post, but otherwise Carson was not overly busy before the break.
Dundee had the best chance of the first half when Owen Beck got to the byline and cut the ball back for Luke McCowan, but Hart spread himself to make an excellent point-blank stop.
Lagerbielke replaced Phillips at the interval and Celtic quickly created their best chance so far as Turnbull set up Furuhashi, who blazed well over the bar.
The opener soon came from nothing and Dundee missed a chance to get back in the game when McCowan shot just wide from 18 yards following a counter-attack.
Dundee switched off when Furuhashi scored as Zach Robinson lay in pain near the touchline and the Dundee midfielder soon went off injured.
Johnston hit the bar following Maeda’s backheel before the right-back’s forward pass sparked the move that led to the third goal.
Amadou Bakayoko missed a good chance for a consolation after being set up by McCowan, while Johnston hit a post from close range late on.