Selby, currently ranked number one in the world, edged into the quarter-finals with a 4-3 victory over Robbie Williams, but dropped just three more frames across his next three matches to take the title.
Swail, twice a World Championship semi-finalist, had dropped off the main tour last season after 22 years as a professional, but had impressed in beating the likes of Shaun Murphy and Barry Hawkins to get to the final.
Selby, though, race into a 3-0 lead and sealed the contest with a break of 85.
The man nicknamed the 'Jester from Leicester' said he had finally put a neck injury, sustained at the end of last season, behind him.
"I've been struggling for a while with the injury and my game so it's great to win another title," Selby said.
"I didn't make many mistakes in the final and that gives me a lot of confidence going into the rest of the season. And it's good to be guaranteed a place in the PTC Grand Finals already."
The PTC events continue with UKPTC3 from September 5-9 in Gloucester.
Ryan Day 4-2 Jamie Jones
Pankaj Advani 4-3 Mark King
Michael Wild 3-4 Ken Doherty
Robbie Williams 3-4 Mark Selby
Andrew Norman 4-3 Ricky Walden
Shaun Murphy 2-4 Joe Swail
Michael White 4-2 Dominic Dale
Barry Hawkins 4-1 Thepchaiya Un-Nooh
Ryan Day 1-4 Pankaj Advani
Ken Doherty 0-4 Mark Selby
Andrew Norman 3-4 Joe Swail
Michael White 1-4 Barry Hawkins
Pankaj Advani 2-4 Mark Selby
Joe Swail 4-3 Barry Hawkins
Mark Selby 4-1 Joe Swail