Watford was one of five players in double figures for the Hoosiers, scoring 11 points at the free throw line and hitting three treys. Will Sheehey added 18 points.
Sam Houston dropped to 1-2 for the year. Paul Baxter led the Bearkats with nine points. Marquel McKinney added eight.
Indiana never trailed, jumping out to a 16-2 lead and building to a 52-25 margin at halftime.
The Hoosiers went 30-of-53 from the field (56.7%) including nine three-pointers. Sam Houston was limited to 16-of-53 (20%) shooting. Indiana hit 30-of-44 at the line while Sam Houston made eight in the Bearkats 12 free throw attempts.
Nathaniel Mason scored seven points for Sam Houston and Michael Holyfield added five points. Indiana out-boarded the Bearkats 45 to 23.
Sam Houston returns to Bernard G. Johnson Coliseum Monday night to begin the Progressive Legends Classic sub-regional tournament.
Southern Mississippi, Liberty and UC-Irvine will be the other three participants. Games are at 5 p.m. and 7:15 p.m. each night with the Kats playing in the nightcap daily.