Scott Williams upset the odds on Wednesday evening to clinch a first ranking title despite not owning a PDC Tour Card, making him the first player to do so since Krzysztof Ratajski in February 2018.
The 32-year-old from Lincolnshire claimed an 8-5 win over Aspinall to cap off a mightily impressive run to the final, which included wins over Jonny Clayton and Rob Cross.
As a result of his triumph, Williams left Germany with the £12,000 prize fund in his pockets.
Williams' superb run began with victories over Gary Blades and Danny Baggish, and a stunning 11-dart leg saw him clinch a 6-5 win over Jonny Clayton in round three, after the Welshman had posted 111 and 108 averages in his opening two games.
Reigning World Cup champion John Henderson was next in line, and after toppling the Scot, Williams then managed a 6-4 win over Rob Cross in the quarter-finals to mark the furthest he had been in any Players Championship this year.
In the final four, two-time Pro Tour winner Chris Dobey also became a victim of Williams' unstoppable momentum, with the eventual winner booking his place in the final with a 7-4 win.
Williams also made a stunning start to the final, racing into a 2-0 lead against a stunned Aspinall who suffered a slow start to the showpiece.
However, the Stockport star then reeled off three consecutive games to fight his way back into the lead, the first of which was an impressive 13-darter.
Williams responded with a 12-dart break in leg nine to reassert his authority and worry Aspinall, and his opponent's nerves showed in the following leg, with Aspinall squandering five darts to allow Williams to extend his lead.
Aspinall was gifted a temporary reprieve when Williams missed three match darts on the verge of an 8-4 victory, but he regained his composure shortly after and landed two 180s en route to a 14-darter to wrap up the victory.
"I'm so pleased, I cannot believe it," said Williams, a winner of three Challenge Tour titles in 2022.
"I am beating players that people see in big TV events every week. That is an unbelievable feeling.
"My main target was to get into the World Championship. I'm also looking good for the Players Championship Finals now. I'm so happy. I want people to see me and know who I am."