Of course, in this wild and chaotic Premiership season we are watching unfold, one of the most heavily criticised signings in recent Scottish football history became the match winner in a crucial Old Firm derby.

Youssef Chermiti, bought from Everton for a reported deal worth £10m, external just four months ago, had two Rangers goals at the time he and his team-mates came out of the tunnel at Celtic Park with a one-goal deficit to make up.

Fifteen minutes later, the Portuguese striker's tally for the season had doubled as the Ibrox side roared to a remarkable comeback victory at the home of their city rivals.

"You have two stories today," Rangers boss Danny Rohl told BBC Scotland following the statement win.

"One, we can turn things in one half to come back 3-1 and win this game. The second story, we have a centre-forward in Youssef who scores fantastic goals."

"This is what I work for, this is what everyone works for," were the words of Chermiti.

"If you want to be a big player, you have to play for the big clubs and [deal with] big pressure," he added on Sky Sports.

The 21-year-old had no goals in more than two years when he ended a challenging spell at Everton for a fresh start at Ibrox.

His early minutes were a source of frustration for the Rangers support and a source of comedy for opposing fans during a testing introduction under former head coach Russell Martin.

He opened his account in Rohl's first Scottish Premiership game as Rangers boss against Kilmarnock in October but did not add to his tally until two months later, a consolation in the defeat at Hearts a fortnight ago.

Back-to-back starts followed against Motherwell and St Mirren, and while there were no goals, he delivered improved showings and was included in the XI at Celtic Park, even with Bojan Miovski returning to the squad.

But in a disjointed and ragged first half for Rangers, Chermiti cut an isolated figure, completing just three passes in 45 minutes as Celtic overwhelmed Rohl's men.

By the full-time whistle, though, the forward had scored twice while winning more duels and completing more dribbles than any other player on the pitch.

He showed a clinical side that many have felt he has lacked, scoring with his only efforts in a hostile environment.

His first goal, which levelled the game, was a poacher's finish, getting himself between the posts to convert Nico Raskin's ball across goal before calamitous Celtic defending allowed him to drive forward and finish a second just nine minutes later.

"Paying back a chunk of that transfer fee," former Rangers winger and coach Neil McCann said on Sky Sports as Chermiti wheeled away to celebrate in front of a delirious pocket of away fans.

Former Rangers striker Kris Boyd added: "There have been questions asked of him because of his fee, rightly so, I've been one of them asking the questions.

"But, tell you what, to come to Celtic Park and get two goals..."

Talk of both Old Firm clubs needing a new first-choice centre-forward has dominated the build-up to the Scottish transfer window opening.

All of a sudden, that talk in Govan has hushed somewhat.