South Dakota-based police officer Bruguier had won through Tuesday's Qualifiers in Las Vegas to secure a spot in the $25,000 North American Championship.
The 35-year-old made a nerveless transition onto the televised stage as he defeated Ohio's Dennis "DJ" Sayre 6-3 in the quarter-finals and Canadian youngster Dawson Murschell 6-3 in the semi-finals.
He then came from 3-1 and 4-2 down in the final against Canada's Richardson to claim the $10,000 first prize as well as a coveted place in the sport's biggest tournament, the William Hill World Darts Championship.
Scottish-born Richardson made the stronger start, winning the opening two legs and recovering from a miss in the third to land a 180 which left double 18 for a 13-darter in leg four.
He then responded to an 89 finish from Bruguier in leg five by taking out double four to lead 4-2, but a miss at the bull in leg seven gave Bruguier his chance.
The newcomer took out double 16 to hit back, 80 to level and then landed tops to lead for the first time at 5-4.
Richardson showed his quality by landing a 180 and double ten to force a decider as the pair entered a one-leg shoot-out for the title - but Bruguier opened with two 140s and then scored 123 before taking out 98 for a 12-darter to claim glory.
"I can't believe it, I'm ecstatic," admitted Bruguier, who had battled from behind in both the semi-finals and final. "This was the goal and I'm happy to have achieved it.
"Dawson and Dave were both hitting their doubles in the first half and then the break came, and thankfully I started picking up and hitting doubles after the break.
"There was a time in the first qualifier where Shawn Brenneman knocked me out and it made me refocus. I put a lot of practice time in after that. To play the way I performed on stage I'm very happy.
"I cannot thank the PDC enough for coming over here, and Fox Sports and everybody else who had a hand in this, it's absolutely amazing."
Bruguier added: "I can't wait for the World Championship, I've got no idea what to expect but I'm looking forward to it."
Bruguier had hit six doubles from eight attempts in his impressive opening win over Sayre, who took out a 140 finish but was unable to halt his fellow American's effort.
He then came from 3-1 down to win five straight legs as he overcame 21-year-old Murschell in the last four, as the Canadian youngster's impressive TV debut ended in disappointment.
Richardson - who competed in the 2015 World Championship - had opened his 6-1 quarter-final win over Shawn Brenneman with checkouts of 120 and 100, and repeated that scoreline in his semi-final defeat of Chris White, hitting six doubles from nine attempts.
Richardson praised Bruguier's display, and said: "It puts a little more pressure on you when you know you're playing a guy who's finishing as well as he is.
"I tried and in both matches he played he scored really well, his finishing was unreal. He was just relentless through the whole match."
White had landed a 170 checkout during his 6-1 quarter-final defeat of Jayson Barlow, while Murschell came from 3-1 down in his opener against Nova Scotia's David Cameron to claim victory in a deciding leg.
All eight North American players now progress to take on eight of the world's leading players in the two-day U.S. Darts Masters, which begins on Friday at the Tropicana Las Vegas - A Doubletree by Hilton.
Bruguier will meet Welshman Gerwyn Price, the 2017 UK Open finalist, while California-based White takes on reigning World Champion Michael van Gerwen.
Richardson plays German youngster Max Hopp - the former World Youth Champion who is making his World Darts of Darts debut - while Murschell drew multiple TV champion James Wade and Barlow and Cameron take on former World Champions Gary Anderson and Raymond van Barneveld respectively.
World number three Peter Wright, the reigning UK Open champion, will play Brenneman, while Sayre takes on another World Series of Darts debutant, Northern Ireland's Daryl Gurney.
The World Series of Darts event then concludes on Saturday with the quarter-finals, semi-finals and final.
2017 North American Championship results
Thursday July 13
Quarter-Finals
Chris White 6-1 Jayson Barlow
Dave Richardson 6-1 Shawn Brenneman
Willard Bruguier 6-3 Dennis Sayre
Dawson Murschell 6-5 David Cameron
Semi-Finals
Dave Richardson 6-1 Chris White
Willard Bruguier 6-3 Dawson Murschell
Final
Willard Bruguier 6-5 Dave Richardson
Fast Results
Scores
Racecards 
