Spieth faces Davis and Homa gets Kim in Presidents Cup singles
The United States carries an 11-7 lead into the final day at Quail Hollow, where a fightback by the global squad offers an outside chance at some drama.
The Americans, chasing a ninth consecutive title, own an 11-1-1 edge in the all-time rivalry and have never lost on home soil.
The US squad needs 4.5 points while the Interntionals must take 8.5 to claim the trophy outright for the first time since 1998.
Justin Thomas, who was 4-0 in pairs matches alongside Spieth, faces Kim Si-woo in the opening match of the afternoon.
Spieth follows against Australia's Davis, who birdied the last three holes Saturday to produce a 1-up victory, with Japan's Hideki Matsuyama facing Sam Burns third and Patrick Cantlay playing Aussie Adam Scott after that.
World number one Scottie Scheffler, the reigning Masters champion who went 0-3 in pairings with Burns, will meet Colombia's Sebastian Munoz.
Canada's Taylor Pendrith meets Tony Finau and Tokyo Olympic champion Xander Schauffele faces Canada's Corey Conners.
South Korea's Im Sung-jae plays Cameron Young with South Korean Lee Kyoung-hoon meeting Billy Horschel just ahead of Homa taking on Kim, whose 18th-hole birdie brought the Internationals a dramatic win Saturday.
Sunday's two final matches send two-time major winner Collin Morikawa against Chile's Mito Pereira and Kevin Kisner against South African Christiaan Bezuidenhout.
