The 18-year-old, from Sprotbrough, surged to a stunning 4-0 victory in Sunday’s final against Kirsty Hutchinson.
She took just 28 minutes to complete a memorable win and dropped just one leg in the process.
Greaves also recorded the highest average ever recorded in a women’s world final (92).
A much-improved prize fund for this year’s tournament saw the Doncaster teenager collect a winner’s cheque of £25,000.
Opponent Hutchinson, from Durham, was left shrugging her shoulders and smiling on the oche, simply unable to live with the relentless Greaves.
She took the opening set within five minutes and dropped just one leg on her way to a 2-0 lead.
From that point there was no way back for Hutchinson and Greaves went on to complete a straight sets win without losing another leg.
She told Quest TV: “I just feel so happy. There’s no words to describe what I’m feeling. I cannot believe what I’ve just won.
"I’ve lost some of the most amazing people in my life and just to win it for them, I just feel [...], yeah.
"I’m done now! I don’t care what else I win. This is it, I’m just buzzing!”
Greaves had earlier eased to victory against Lorraine Winstanley in her semi-final on Saturday night, winning 3-0 in just over 30 minutes.
She beat Hungary’s Veronika Ihász 2-1 in the last 16 before a 2-0 win over the Netherlands’ Aileen de Graaf in the quarter-finals.
The Doncaster College Student went into the tournament in good form after winning all three ladies singles tournaments at last month’s Isle of Man Darts Festival.
She reached the semi-finals at the 2020 BDO World Championship during which she turned 16.