The PDC Unicorn World Youth Champion has previously won two Youth Tour events but confirmed his status amongst the world's elite stars with a relentless and mature display against the world number four.
Brown had already overcome Alan Norris, young rivals Jamie Lewis, Ricky Evans and Dirk van Duijvenbode as well as world number five Peter Wright and in-form Scot John Henderson in Sunday's £60,000 event.
He then took on Lewis in the final, and claimed the title in style with a brilliant display.
Brown took out 130 twice for 12-darters as he took a 2-1 lead, while Lewis landed a 180 in the second and another maximum as he levelled with a 14-darter.
Brown then landed a maximum in a 13-darter to edge 3-2 up before breaking throw in the sixth after posting another 180 and double five.
Lewis broke back with a fine 13-darter, landing a 177 and double ten, but saw his chance to level in the next ended when Brown fired in a 177 of his own to set up double 14 for a 13-darter, which moved him into a 5-3 lead.
Brown then scored 140, 180 and 145 in the next to set up 36 for the title, and though he initially missed three darts at double 18, returned to hit the bed for another 13-dart finish as he completed a memorable win.
"It's overwhelming," said Brown. "Adrian got the better of me the last time we played, he destroyed me, so I'm glad I got him this time - he's a Premier League player so you know what to expect.
"The Youth Tour has helped me over the last couple of years to progress onto the latter stages of the ProTour. In my previous final against Robert Thornton I lost 6-5 and in that last leg I'm glad the double 18 went in in the end!"
The £10,000 prize money will move Brown into the provisional qualifying places for July's BetVictor World Matchplay in Blackpool, and he admitted: "The World Matchplay is at the back of the mind of every player.
"I've got to move onto the next competition now, we're back in Crawley in a couple of weeks and I know if I'm not grounded then somebody's going to beat me 6-0 - I need to keep my feet on the ground and relax and play my normal game, but I'll enjoy this first."
Lewis' run to the final saw him bounce back well from his double of defeats in last Thursday's Betway Premier League in Birmingham.
He enjoyed two whitewash wins in his first three games on Sunday, against Mick Todd and Steve West, and also defeated Matt Clark, Mervyn King, Mensur Suljovic and Gerwyn Price on his way to the decider, picking up £5,000 prize money for his efforts on the day.
Price was appearing in his second PDC semi-final since turning professional in 2014, with the £2,500 prize money consolidating his place in the qualifying positions for July's BetVictor World Matchplay in Blackpool.
After defeating youngsters Ross Smith and Nathan Aspinall, he then knocked out Vincent van der Voort, Brendan Dolan and James Wade - the latter two in a deciding leg - as he won through to the last four, where despite a 170 finish Lewis proved too strong.
Henderson continued the form which had taken him into the German Darts Mastes final a month ago as he battled through to the semis, and like Price improved his position inside the World Matchplay's qualifying places.
After overcoming Wes Newton 6-5 in his opening game, he then saw off Mickey Mansell, Scottish duo Robert Thornton and Jamie Bain and Dave Chisnall as he progressed through the field.
Wade had been the runner-up in both of the weekend's previous Players Championship events, and ended the weekend with a quarter-final appearance.
Having been the top seed on the day, Wade overcame Luke Woodhouse, Jamie Robinson and Robbie Green before edging out Holland's Jermaine Wattimena 6-5, but after finishing 142 and 170 to take Price to a deciding leg missed two match darts as the Welshman ended his hopes.
Wade's Premier League rival Dave Chisnall also went out in the last eight alongside Austrian star Mensur Suljovic and Saturday's Players Championship winner Peter Wright.
The Dutch quartet of Wattimena, Benito van de Pas, Jan Dekker and Dirk van Duijvenbode were joined by English youngster Adam Hunt, Scotland's emerging Jamie Bain and top 16 stars Mervyn King and Brendan Dolan in reaching the last 16.
Gerwyn Price 6-5 James Wade
Adrian Lewis 6-4 Mensur Suljovic
John Henderson 6-4 Dave Chisnall
Keegan Brown 6-4 Peter Wright
Adrian Lewis 6-4 Gerwyn Price
Keegan Brown 6-4 John Henderson
Keegan Brown 6-3 Adrian Lewis
Winner £10,000Runner-Up £5,000
Final - Leg-By-Leg
0-0 - Keegan Brown wins the bull and throws first.
0-1 - Brown takes the opening leg with a superb 12-darter, scoring 131, 140, 100 and finishing 130 on double five.
1-1 - Lewis lands a 180 and finishes 74 on tops to level.
1-2 - Brown's outstanding start continues as he opens with a 180 before finishing 130 for another 12-darter, this time ending on double five.
2-2 - Lewis kicks off the leg with a maximum before levelling by landing double ten for a 14-darter.
2-3 - Brown edges back in front with a 13-darter, opening with another 180 before finishing tops.
2-4 - Brown scores 140, 180 and 105 to be first to a finish before breaking throw on double five in 15 darts.
3-4 - The superb standard continues as Lewis lands a 177 and double ten to break with a 13-darter, after Brown misses double 16 to extend his advantage.
3-5 - Brown breaks once again with another 13-dart leg, landing a 177 to leave double 14 after Lewis is unable to finish 135.
3-6 - Brown scores 140, 180 and 145 to leave 36 after nine darts, and though he initially misses three darts at double 18 he returns to hit the bed to complete a 13-darter for the title, his first PDC ProTour triumph.