The dynamic duo shot 13-under through the two rounds to defeat Scotland Schmidt and Jack Townsend of San Diego, Calif., by one shot, as Schmidt and Townsend finished at 12-under.
"We really played solid and tried to be patient," Geyer said. "Nothing in particular, just really trying to be one shot at a time."
Geyer recorded a birdie on the par-4 No. 18 to give his team the one-shot win at 13-under. Geyer and Davis were one of three groups tied for first place after the first round. Geyer and Davis shot rounds of 65-66 to win the Championship.
"With four holes to play, we knew we needed to push and just tried to have two good looks each hole," Geyer said. "Billy played incredibly and really was the team captain. I just tried to draft as best as I could."
Schmidt and Townsend both made a bogey on No. 18 to fall from 13-under to 12-under.
Roy Kim of Los Angeles, Calif., and Sean Birren of Upland, Calif., finished in solo third place at 11-under.
Davis shot two rounds of 1-under 71 to finish 2-under, missing the cut but hovering around the cut line for both days.
Davis, who is the twin brother of 2022 August National Women's Amateur champion Anna Davis, made nine birdies in 36 holes. He hit all 28 fairways and hit 25 of 36 greens.
It has also been a solid year for Geyer, who won the 2023 SCGA Mid-Amateur and finished T9 at the SCGA Public Links.