Kappler cleared seven fences in the jump-off in 32.533 seconds, beating out Courtney Phibbs, riding Snepts (33.435), and Laura Chapot on Little Big Man (33.950).
It was Kappler's first title and snapped a string of four straight championships by McClain Ward.
"He's a very small horse," Kappler said. "But I just feel excellent on that horse. Right now I'm just inching him up and seeing how far we can go.
"There's lot of little horses that did well here. And little horses are just athletes."
The weather made it difficult for riders to navigate the course. Four riders withdrew their horses during the event.
Kappler, Laura Chapot and Alison Firestone were all in contention for the leading rider title, with each rider reaching that position by divergent paths.
Chapot had placed herself in position by going the smaller route, scoring three victories of 10 points each in the smaller jumping events. She elected to bypass the Grand Prix on Thursday night, because she felt the horses weren't ready for that level of competition.
Kappler placed himself in a position to win by taking the major events, including the Grand Prix, which was worth 15 points. Firestone entered more events than Chapot and Kappler, placing first in one and finishing high enough to score in various others.
Entering the final jumping event, Kappler had the highest point total at 41, followed by Chapot with 32 points and Firestone with 27.5.
For the second straight year, Chapot won the open jumper title, riding Little Big Man again. The 11-year-old Dutch warmblood was the first horse of four in the 27-horse field to successfully clear all 13 fences in 72.342 seconds.
Small by normal show jumping standards, Little Big Man attacked the fences without any hesitation.
Amateur owner hunter-18 to 35 years of age: 1, Saint Nick, rider/owner Caroline Moran. 2, Jupiter, rider/owner Lindsey Phoebus. 3, In Return, rider/owner Caroline Moran.
Amateur owner hunter stake-18 to 35 years of age: 1, Eminem, rider/owner Katie Polk 2, Jupiter, rider/owner Lindsey Phoebus. 3, Saint Nick, rider/owner Caroline Moran.
Amateur owner champion-18 to 35 years of age: 1, Saint Nick, rider/owner Caroline Moran 2, Jupiter, rider/owner Lindsey Phoebus.
Amateur owner hunter-over 35: 1, Estrella, rider/owner Betty Oare. 2, Carlyle, rider/owner Kate Gibson 3, Gershwin Gershwin, rider/owner Kimberley A. Quinn.
Amateur owner hunter-over 35 stake: 1, Icon, rider/owner Laurie Stevens. 2, Estrella, rider/owner Betty Oare. 3. Small Talk, rider/owner Rachel Spencer.
Amateur owner hunter champion-over 35: 1. Estrella, owner/rider Betty Oare 2, Lennox, rider/owner Sandra Brown.
Amateur owner hunter grand champion: 1, Estrella, owner/rider Betty Oare.
Working hunter-fox hunting field performance: 1, Sam I Am, rider Mary Canner, owner Bay Bridge Farm. 2, I, Claudius, rider Leslie Ducharme, same. 3, Alleged Alibi, rider Megan McCann, same.
UPHA junior hackney pony classic: 1, Romeo's Warrior, rider Marjorie Kenney, same.
Three-gaited saddle horse-junior exhibitor stake: 1, Tahiti Petey, rider Brittany Davis, same. 2, Helen A Handbasket, rider Adrienne Hariry, owner Jessica Schuett.
$350 hackney/harness pony pleasure driving championship: 1, Early Edition, rider Jane Mueller, same. 2, Atta-Boy, rider Kevin P. Gibbons, same. 3, Token's Classic, rider Hannah M. Salvatore, owner Carol B. O'Neill & Hannah M. Salvatore.
$350 three-gaited English country pleasure championship: 1, CH Heir Tight, rider Lisa Keno, owner Leigh Keno. 2, SS Inner Vision, rider Kirby Tapper, owner Tom Wentz. 3, The King's Talent, rider Stephanie Shertzer Lawson, same.
$1500 single hackney horse championship: 1, Heartland Blizzard, rider Karen Waldron, owner Bent Tree Farm, Ltd. 2, Splendid Nicholas, rider Misdee Wrigley, same. 3, Brickell Prince, rider Mark H. Schofield, owner Misdee Wrigley.
$350 single roadster pony amateur championship: 1, Heartland Memory, rider/owner Mary Campbell. 2, Dun Haven Highly Impressive, rider/owner Alan Nath.
Show jumping hall of fame amat-owner jumper classic: 1, Camerino, rider Jessica Siuda, owner Windward Farm & Siuda Family. 2, Jolien Contender, rider Rebecca A. Astrom, owner Twin Oaks Farm & Pamela Astrom. 3, Mont Blanc Land of Kings, rider Amanda Gumberg, owner Skara Glen Stables, Inc.
Amateur-owner jumper championship and reserve champion: 1, Camerino, owner Windward Farm & Siuda Family.
$40,000 open jumper-time first jump off: 1, Tango, rider Chris Kappler, owner, Falcon Farm LLC, 32.533 time. 2, Snepts, rider Courtney Phibbs, owner Court-Lin-Frae Farm, 33.435 time. 3, Little Big Man, rider Laura Chapot, same, 33.950 time.
Contact suburban staff writer Joe Santoliquito at 610-313-8028 or firstname.lastname@example.org.