His goal-scoring talents were already well known. European giants Real Madrid and Manchester United were among his admirers.
But his feats at City have defied belief at times and set new standards in England's top flight.
With 36 goals in the Premier League, he set a new benchmark in the division by breaking the record of 34, which was jointly held by Andy Cole and Alan Shearer. It had stood for 29 years.
He scored 52 in all competitions, including six hat tricks.
Haaland's five goals against Leipzig in the Champions League matched the record held by Messi and Luiz Adriano for the most in a single game in European soccer's top club competition.
He also became the fastest and youngest player to reach 30 Champions League goals.
"His mentality is to score more, more," City manager Pep Guardiola said.
While he will likely be the player Inter Milan fears most in Saturday's final in Istanbul, Haaland is on something of a scoring drought heading into the game.
Just one goal in his last seven matches represents his worst run for five years, dating back to when he was still establishing himself at Norwegian team Molde.
That recent dry spell, however, has done nothing to shake the sense that he is one of the few players capable of taking over from Messi and Ronaldo as soccer's next global icon. And at 22, he is still developing his game.
"I am still young. I can improve a lot and I am at the perfect place, to work with the best coach and players in the world," he said, describing Guardiola as a "detail freak.... There (are) always things you can get better at."
Haaland's all-round game has improved after developing more of an understanding with his City teammates. He was outstanding, for instance, in the 4-0 win against Real Madrid in the Champions League semifinals, despite not getting on the scoresheet.
Just as Messi and Ronaldo's rivalry helped drive them to even greater heights - sharing 12 Ballon d'Or trophies between them - Haaland's primary competition for the title of the world's No. 1 soccer player is likely to come from Mbappe and Vinicius. But while Haaland may not have their finesse or intricate footwork, his raw power, athleticism and scoring instinct sets him apart.
The greatest players, however, are judged by the trophies they win. Messi's World Cup triumph with Argentina in December has, for many, settled the debate as to who is the greatest out of him and Ronaldo, who has never won the competition.
Haaland is already playing catch-up in terms of trophies in comparison to Mbappe and Vinicius. But he's one game away from adding the Champions League to his Premier League and FA Cup collection.
Mbappe, a World Cup winner with France in 2018, is still to triumph in the Champions League.
Brazil star Vinicius won it last year with Madrid.