Davis's first prominent tennis match was a doubles competition for the California state championship in 1913 in which he and Lin Murray were eliminated by Clarence Griffin and John Strachan.

[4][6] The New York Times profiled him as exemplary of the emerging California style of powerful "cannonball service" which Maurice E. McLoughlin had used to become national champion.

[9] In the 1916 Pennsylvania State Championship Davis scored a memorable victory over Bill Tilden in the semifinal, 3–6, 6–3, 13–11, and then claimed the title against Graig Biddle in the final.

[3] In 1920, Davis reached the final of the men's doubles championship with Roland Roberts but were defeated by fellow Californians Clarence Griffin and Bill Johnston in three straight sets.

His best Grand Slam singles result came at the 1921 U.S. National Championships where he reached the semifinals and lost in straight sets to multiple champion Bill Tilden, though the first went to 10-8.