Tennell, of Carpentersville, Illinois, turned in a mistake-free program en route to a score of 73.79 points, breaking the mark of reigning U.S. champion Karen Chen (72.82, 2017).
Mirai Nagasu (Pasadena FSC) is in second place with a score of 73.09. Nagasu, of Arcadia, California, is the 2008 U.S. champion and a 2010 Olympian. Chen (Peninsula SC), a native of Fremont, California, is in third place with 69.48 points.
Three-time U.S. champion Ashley Wagner (SC of Wilmington) sits in fifth place with 65.94, behind Angela Wang (Salt Lake Figure Skating), who scored 67.00.
Competition resumes tomorrow with the pairs and men's short programs. The ladies free skate is set for Friday, January 5, at 3:45 p.m. PST at SAP Center in San Jose. There are 22 ladies competing in the field.
For more information, visit the U.S. Figure Skating Fan Zone.