27-goal sensation Haaland has been linked with a $184 million summer transfer to the likes of Barcelona, Real Madrid, Manchester City and Manchester United, and the 20-year-old finished with a flourish at Borussia Dortmund's Signal Iduna Park, scoring early and late in a comfortable 3-1 win over Bayer Leverkusen.

The Norway prodigy then swapped shirts with veteran referee Manuel Grafe, celebrating in the official's branded black shirt for a ceremony in which Dortmund's players celebrated their recent triumph in German domestic cup competition DFB-Pokal.

Grafe, whose enforced retirement from the German top flight has been described as "a joke" by Dortmund sporting director Michael Zorc, wore a t-shirt reading 'danke' as he stripped off to claim the priceless memento before posing for photos with Haaland.

The popular referee is being forced to retire from Bundesliga duties because the rules do not allow officials to continue past the age of 47.

Grafe had not even been born when Bayern Munich and Germany legend Gerd Muller set the record for the number of goals in a season at the end of the 1971/72 campaign, finishing on a remarkable 40 goals.

Muller's record had been under threat from some time by current Bayern goal machine Lewandowski, although the Poland captain had only equaled his haul going into the 90th minute of the final match of his club's season.

That was an unlikely state of affairs given that Bayern had already scored four times, and lethal Lewandowski would not be denied.

Fellow Polish player Rafal Gikiewicz, who had produced a superb save to thwart his compatriot shortly beforehand, could only parry an effort by former Manchester City winger Leroy Sane, allowing Lewandowski to pounce with what was almost the last kick of the game.

"I want to dedicate this goal to my mother because she has her birthday today," Lewandowski told BT Sport, also paying tribute to outgoing manager Hansi Flick and his coaching team as he departs to guide the Germany national team.

"I don't know exactly what I've done yet but emotions are very high. I have to say that I never dreamt of breaking this record because I thought it was impossible when you have 34 games [in a season], and I played 29.