Rachel Blunt led the Lady Bearcats with 22 points. Natalie Hayes scored 14 and Charlotte Johnson added 12, hitting three 3-pointers.
"I was glad to see Natalie Hayes score some points for us," said Dexter coach Gavin Miller. "She's a very athletic girl. I'm hoping she will continue that trend."
Dexter outscored Senath 20-13 in the first quarter, 16-9 in the second, 22-11 in the third, then 20-15 in the fourth. Senath was led by Stef Cunningham with 12 points, Christina Motts with 10 and Emily Jamerson with 10.
Dexter played most of the game without point guard Hannah Burleson, who is recovering from an injury.
"We played her too many minutes against Sikeston," said Miller. "It took her a couple of days extra to get healthy."
Dexter (2-0) will travel to Doniphan on Thursday.
CAPE GIRARDEAU -- Sierra Ellis scored 21 points and Sommer McCauley added 19 as Notre Dame blew past New Madrid County Central, 71-20.
Notre Dame was in control of the game all the way, outscoring the Lady Eagles 13-2 in the first quarter, 22-7 in the second, 22-4 in the third, then 14-7 in the fourth.
Smith paced NMCC with six points.