Glasgow (AFP) - Kyogo Furuhashi took his tally for the season to 20 goals as Celtic eased into the last 16 of the Scottish Cup with a 5-0 win at home to second-tier Morton on Saturday.

The Japan forward matched his tally for last season thanks to a first-half double in the fourth-round tie at Parkhead.

Aaron Mooy also scored twice, with David Turnbull on target as well.

Morton had reason to feel aggrieved by the way Celtic went ahead from the penalty spot following a particularly harsh VAR decision against former Hoops defender Efe Ambrose.

Celtic manager Ange Postecoglou, who has made his opposition to VAR clear, had no desire to revisit the topic as he praised his side’s approach to a potentially tricky cup tie.

“I thought the attitude of the boys was great,” he said. “You go into these games with a bit of trepidation about how the boys will react and I thought they reacted well.”

Morton could have broken the deadlock when Lewis Strapp was left one-on-one with Joe Hart only to shoot straight at the former England goalkeeper.

At the other end, Celtic’s Liel Abada had a shot blocked and play continued, with most spectators in the crowd thinking no more about the effort.

But VAR Craig Napier eventually spotted that Abada’s shot had come off the foot of Jack Baird then bounced up away from goal and brushed Ambrose’s arm, which was slightly away from his body.

That was enough for Napier to decide on-field referee Kevin Clancy had made a “clear and obvious” error.

Having looked at the pitchside monitor, Clancy awarded Celtic a penalty.

“No-one really sees anything,” said Morton manager Dougie Imrie. “I don’t know how Efe’s meant to get his hand out of the road. It takes a deflection and it’s so close.

“I just don’t know how they can give a penalty.”

Mooy sent Brian Schwake the wrong way from the spot in the 18th minute. Three minutes later Celtic were 2-0 ahead when Ambrose took a heavy touch on the edge of his box and Abada played in Furuhashi.

Celtic went further ahead in the 42nd minute when Furuhashi laid the ball back for Turnbull, who let fly with a first-time shot from 22 yards.

Furuhashi made it 4-0 in stoppage time after Grant Gillespie had taken a fresh-air swipe at Abada’s cutback.

Morton denied Celtic a second-half goal until six minutes from time when Mooy finished from close range.

Premiership high-flyers Livingston avoided a Cup upset by coming from behind to win 3-1 at Stenhousemuir with a quick-fire treble.

League Two Stenhousemuir took the lead in the first half through defender Nicky Jamieson.

Scott Pittman, however, equalised in the 52nd minute and Steven Bradley then struck twice before the hour mark to turn the tie on its head.

Top-flight Kilmarnock just did enough to see off League Two leaders Dumbarton, and Dundee United also had a difficult afternoon before defeating Stirling University 3-0.

Scottish Cup-holders Rangers are in fourth-round action later Saturday away to St Johnstone.

Hearts, last season’s losing finalists, make the short trip to Hibernian for an Edinburgh derby on Sunday.