Rangers progressed to the quarter-finals of the Premier Sports Cup thanks to substitute Cyriel Dessers' controversial opener and a late Ross McCausland dink that sealed victory over St Johnstone.
The holders were on top for most of the match at Hampden but struggled to make the breakthrough until Rabbi Matondo played in Dessers, who tangled with defender Jack Sanders.
Referee Matthew MacDermid seemed to give that as a foul before Dessers danced into the box and produced a fine finish but the goal was ruled out until VAR intervened.
St Johnstone were left furious when the strike was ultimately awarded as they clearly felt play had been stopped by the referee.
Post match, the Scottish FA offered guidance that MacDermid blew his whistle after Dessers' shot had crossed the line.
Rangers produced numerous chances throughout, repeatedly exposing St Johnstone down the left side in particular, with Danilo denied from close range on his first start this season. Too often, though, the final product was off target.
Craig Levein’s side twice came close to punishing that wastefulness. Andre Raymond got the break of the ball but saw a great chance blocked before in-form Adama Sidibeh struck the outside of the post from close range.
Rangers winger Vaclav Cerny had looked certain to break the deadlock from the angle but flashed the ball just outside the far post just before Dessers’ intervention.
The hosts pushed on for a cushion but it was Sidibeh who had a wonderful opportunity blocked from close range in injury time, before McCausland’s cute dink over Josh Rae sealed Rangers' progression.
Deserved win overshadowed by controversy
You can’t look past the decision-making that led to Dessers’ goal. Rangers deserved the win but the way they got there is worth further scrutiny.
While the SFA have sought to clarify the confusion over the opener, it will do little to dilute the controversy.
That aside, Rangers did look very strong in getting into promising forward areas but too often lacked the clinical edge that would have made this considerably more comfortable, as they looked to move past their Champions League exit hangover.
The sparse 'home' crowd didn’t help lift that, but job done as far as they will be concerned. They’re through and results are vital right now.
An injury to new singing Robin Propper is another concern as he looked to add something defensively. That is heightened by the fact the backline looked uncertain on occasion.
St Johnstone lived dangerously at times but offered enough to suggest they will trouble sides this season.
They will undoubtedly feel very hard done by given what happened at the goal and can point to two or three excellent chances. A valiant effort that came up short.
What they said
Rangers manager Philippe Clement: "We saw a lot of positive things, good offensive football, dominance and a lot of chances. One key point is to be more efficient with the chances, it has to be a game where you score four or five goals today for me and that’s what we need to do in the future.
"I didn't see the images back but had a feeling when I saw the action live that the referee doubted about the foul of Cyriel [Dessers], but he made the right decision.
"He’s doubting so he didn’t whistle and waited until after the game was dead, if it’s a goal or not, together with his team to make the right decision."
St Johnstone manager Craig Levein: "It was chaos for a while [at Dessers' goal], I didn't know exactly what had happened.
"I thought it was a free-kick to us and had that confirmed by one of the officials, so I didn’t pay much attention for two or three minutes until I realised something was going on and didn't realise VAR was involved until a minute after that.
"I don't think the goal should have stood, simple as that. He [the referee] put his hand up to indicate it was a foul for us, so he gave the decision, what other way can you read that?"