Searle ended a run of three consecutive losses in Players Championship deciders by overcoming Aspinall with an impressive performance.
The 34-year-old - who finished runner-up in November's Players Championship Finals in Minehead - claimed the top prize of £12,000 to conclude Barnsley's triple-header this weekend.
In his opening four games, Searle was tested by Dutch duo Jimmy Hendriks and Jeffrey de Zwaan in a deciding leg while he came out a 6-4 winner against Alan Soutar and Gordon Mathers.
In the quarter-finals, it was much more comfortable as Searle whitewashed Josh Rock before beating former world champion Rob Cross as an 11-darter put him in the final.
Aspinall - looking to win his first ranking title for two years - took out 124 to hit back in leg eight, only to see Searle check out the same finish in the next to restore breathing space before closing out the win.
"It's really pleasing and I saved my best game for the final," said Searle.
"It's a frustrating game! For the last two days I've been playing really well and losing out, and today I started really badly but I got there eventually.
"I scraped through a couple of games but got myself together and played alright after that. I was up for that final - I've lost four in a row and there was no way I was losing that today.
"I didn't care what Nathan was going to hit, I was going to beat him. That was the way I felt and I think that's the way I need to feel more often.
"It is frustrating but I'm pretty laid back and sometimes I'm not up enough for the final - I'm just happy to be there - and I'm trying to change that.
"I want to stay in the top 16 and get even higher. I feel like if I play my game I can beat anyone."
Aspinall's run in the tournament was his best since November, as he continues his return to action following a spell out of competition with a wrist problem earlier this year.
The ex-UK Open winner delivered some sublime darts on Sunday, averaging 109.73 in a victory over Ryan Joyce, 104 to beat Jose de Sousa and 105.83 in his 7-5 semi-final win over Dave Chisnall.
Chisnall was a semi-finalist for the second time in three events this weekend as he continued his bid for a first title of 2022.
Cross, meanwhile, reached his third ranking semi-final inside a month with a run that included four successive ton-plus averages on Sunday.
Northern Ireland's emerging young star Rock claimed a memorable 6-4 win over world number two Gerwyn Price in the last 16 as he reached his second Players Championship quarter-final.
Masters champion Cullen, Vincent van der Voort and Callan Rydz also won through to the last eight.
The day also saw Madars Razma achieve a nine-dart finish against Michael Unterbuchner, although the Latvian ace lost the second round tie 6-1.
The PDC ProTour season continues next weekend, with a double-header of Tour Card Holder Qualifiers for European Tour events followed by Players Championships 12 and 13 in Barnsley.
Coverage from both Players Championships will be streamed live through PDCTV and bookmakers' websites worldwide, including action from two streams simultaneously.
Players Championship 11 results on Sunday
2022 Players Championship 11
Josh Rock 6-4 Gerwyn Price
Ryan Searle 6-4 Gordon Mathers
Joe Cullen 6-4 James Wade
Rob Cross 6-4 Krzysztof Ratajski
Vincent van der Voort 6-2 Steve Beaton
Dave Chisnall 6-1 Ian White
Nathan Aspinall 6-4 Jose de Sousa
Callan Rydz 6-5 Eddie Lovely
Ryan Searle 6-0 Josh Rock
Rob Cross 6-5 Joe Cullen
Dave Chisnall 6-2 Vincent van der Voort
Nathan Aspinall 6-2 Callan Rydz
Ryan Searle 7-6 Rob Cross
Nathan Aspinall 7-5 Dave Chisnall
Ryan Searle 8-3 Nathan Aspinall