Poplar Bluff led 7-6 after one quarter and 13-12 by halftime, but the Bulldogs took control in the third quarter, leading 28-18 on a buzzer-beating shot by Will Holifield.
The Bulldogs put the game away in the fourth quarter.
Sikeston coach Kevin Self was pleased with the win, especially considering Poplar Bluff had defeated Sikeston in two barnburners earlier this season.
"We played really well," said Self. "We mixed up man and zone and that really gave them trouble. We're starting to come together and rely on one another. I like the way we're playing right now."
Sikeston was led by Corey Porter's 10 points. Deaires Tate and Holifield each had eight points. Calvin Grayson had five points. Janeil Hatchett and Ray Clark each had two points.
Sikeston will play in the championship game tonight at 7:15 against the winner of the Jackson-Cape Central game.
DEXTER -- The Dexter freshman team defeated Sikeston's 9th graders for the second time in the past week.
The freshman Bulldog team has now lost three of its last four and currently stand at 9-3 on the season.
Sikeston led 8-7 after one quarter, but Dexter took a 19-16 lead into halftime. Dexter led 35-26 heading into the fourth quarter.
Sikeston was led by Niquavious Dixon's 13 points. Alex Clark followed up with 11 points.
Dexter's freshman team is now 10-2 on the season.
Sikeston's freshmen will be back in action tonight when they host Twin Rivers at 6 p.m. at the Field House.