Kris Boyd says Celtic 'got away with one' as he singles out defender for criticism

However, in a remarkable finish, Giakoumakis slid home an Alexandro Bernabei cross in the fifth and final minute of added time to ensure the league leaders claimed a 2-1 win to move five points in front of their Glasgow rivals ahead of the 3pm kick-offs.

Sky Sports pundit Boyd insisted Celtic "got away with one" and pointed the finger at Scotland Under-21 centre-back Stephen Welsh as he dissected the concession of the set-piece goal that almost proved costly.

"It's something people have looked at as an opportunity to exploit Celtic," he said. "Cameron Carter-Vickers coming back in, there's no doubt you see his aggression, the way you go and attack it.

"But when you look at Stephen Welsh he doesn't even jump. That's your centre-back. You've at least got to go and challenge but he's just standing still there. You've got to do better."

The Celtic goal which could matter more as trio in impress in St Johnstone scare

Postecoglou made six changes from the side that started the Champions League defeat to RB Leipzig at half-time and also subbed Jota at half-time ahead of the return match against the Germans at Celtic Park on Tuesday.

Boyd reckons that the Hoops fringe players who took to the field failed to take their chance.

"They've come away to a difficult venue and won a game of football, especially after being pegged back on 92 minutes," he said.

"But there are players in there who Ange Postecoglou will be looking at now and saying, 'don't come and chap my door becuase I've got my team, I'm sticking to my team, and we'll go from there."

One player who Boyd reckons is deserving of more game-time, however, is Greek striker Giakoumakis, who struck his fourth goal of the season in only his third start.

"As soon as that ball comes in there was only one thing happening," the former Rangers striker said.

"Giakoumakis, for me, I don't think he will look at himself as second choice.

"The stats and numbers he produces is deserving of starting for Celtic.

"There will be some games where Kyogo does start, but Giakoumakis brings something different, there's no doubt about it, and he is a threat.

"When you look at the game today, there weren't many quality balls put in for him to do what he does best but he gets in the areas to score goals and his numbers since he arrived in Scottish football have been through the roof."

Postecoglou hails Celtic resilience and reveals reasons for Jota half-time sub