It didn't take long for him to break into the first team at the Westfalenstadion and he's not looked back since, scoring 46 times in 130 appearances from right wing in just four years.
His incredible amount of game time since moving in 2017, for around £8 million, has shown that he was correct to leave the Premier League behind.
Those minutes also make him the most promising player in the world, according to the boffins at CIES Observatory.
They calculated minutes played for players born in the 2000s weighted with the quality of the league they play in to work out 'capital experience' and decide the most promising player in the world.
Sancho is likely above Haaland because the latter has only played for Dortmund since January 2020, with his previous minutes coming in the Norwegian and Austrian leagues, for Molde and Red Bull Salzburg respectively.
The Norwegian striker has continued his incredible form since moving to the Bundesliga though, scoring 45 goals in 46 appearances since becoming Sancho's teammate.
The 20-year-old is being linked with the world's biggest clubs and is now expected to compete with Kylian Mbappe as the next world's best player.
The Bundesliga is looking good on the table with Alphonso Davies, who won the Champions League last season, splitting the two Dortmund players.
Gareth Southgate will be pleased with the amount of England players on the list, with Sancho joined by Phil Foden and Max Aarons, who is currently playing in the Championship, also in the top 15.
That table is slightly misleading as it's done by birth year and both Bukayo Saka and Mason Greenwood, born in 2001, would make the top 15.
Liverpool's Curtis Jones and yet another Dortmund youngster, Jude Bellingham, make it extremely good reading for the future of English football.
The German side will also either be stacked with talent in a few years time or make a hell of a lot of profit!
Featured Image Credit: PA
Chosen for YouChosen for You
Most Read StoriesMost Read