The Bundesliga 2 sides went head-to-head on Friday in the Hamburg derby in a top of the table clash.
But with less than half an hour gone on the clock, Hamburger conceded a bizarre own goal through their goalkeeper, Daniel Heuer Fernandes.
With snow falling heavily in the German city, the home side were 1-0 up thanks to a 15th minute goal from Jackson Irvine.
Just 12 minutes later, St Pauli had doubled their advantage - this time without having to go anywhere near the ball.
Hamburger's Guilherme Ramos meant to pass the ball along the box to goalkeeper Fernandes. Instead, he sent the ball creeping towards the bottom right hand corner of his own goal.
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The ball then looked to be rolling wide of the post, but Fernandes stepped in and appeared to try to hoof the ball away from danger.
Unfortunately for the goalkeeper, though, the ball hit a bobble and he sliced his effort and fired the ball into the roof of his own net to put the home side 2-0 up.
Fernandes gripped onto his goal and looked to be in complete disbelief as he took in what happened - and fans on social media were equally as perplexed.
"One of the strangest own goals you're ever likely to see," one fan wrote on X, formerly known as Twitter.
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"Andre Onana regen," a second wrote, making reference to Manchester United goalkeeper Onana's struggles this season.
A third added: "Heuer Fernandes is probably one of the best goalkeepers if not the best goalkeeper in that league and now he's become viral for one of the worst own goals you will ever see."
Luckily for Ramos and Fernandes, Hamburger scored twice to equalise in the second half through Robert Glatzel and Immanuel Pherai.
St Pauli remain top of the league, though, still three points above Hamburger after their draw.