Not helped by United's worst start to a season since the early 1960s, Hojlund, who cost 72 million pounds ($90.71 million), looked lost at times as his wait for a first Premier League goal dragged on.
The contrast with City's Norwegian Erling Haaland, who stormed the Premier League in record-breaking fashion in his first season, was almost laughable.
But suddenly the boot is on the other foot.
While Haaland is hardly having a bad season with a league-topping 16 goals, Hojlund no longer looks like a poor imitation.
A day after Haaland missed an absolute sitter in City's 1-1 draw with Chelsea, Hojlund's brace helped United to get a 2-1 win at Luton Town that pushed his side closer to the top four.
Haaland has almost monopolised the record books since arriving in England in July 2022, but Hojlund has now scored in six successive Premier League games, the youngest player ever to do so. Incredibly it took him until after Christmas to register his first Premier League goal.
Now he has seven to his name and there looks to be plenty more where they came from, with Sunday's double at Kenilworth Road illustrating the confidence that has returned.
After 37 seconds, Hojlund seized on a loose back pass and clinically put his side in front. Six minutes later he showed great dexterity and speed of thought by chesting a volley from Alejandro Garnacho past Luton keeper Thomas Kaminski.
"I think I need to say thanks to my team mates and the coach because they have showed me great confidence and kept believing in me," said Hojlund, who arrived from Atalanta in August.
"I knew as well that I could score goals but of course it was annoying I didn't score in the Premier League."
Hojlund's sudden goal surge has been timely for manager Erik ten Hag who was coming under increasing pressure with his team misfiring and Hojlund unable to locate the net.
Not that Dutchman Ten Hag had any real doubts that his striker would eventually come good.
"We recruited him on his character, I knew it was strong. He can really perform under stress and that is something you need as a Man United striker," he said.
"He doesn't get nervous or lose confidence. He has a lot of confidence and I'm sure he will score even more."
No-one is expecting Hojlund to start racking up the sort of statistics Haaland has done for City but he now looks like the kind of striker to help a rejuvenated United embark on a new era.
