Coleman poured in 16 points on 6-of-12 shooting and tacked on a career-high 11 rebounds, while O'Bryant III garnered 11 points and 10 rebounds for the Tigers.
LSU (4-0) has won all four of its games under first-year coach Johnny Jones. It marks the first time since the 2008-09 season that the Tigers have started a season 4-0, when the program won its last SEC championship.
After misfiring on 10 of its first 11 field-goal attempts, LSU went 10 of 15 from the floor over the final 12-plus minutes of the opening half. The Tigers turned an early five-point deficit into a 33-23 halftime advantage.
In the first half, LSU was fueled by a 20-4 run as six different players scored buckets for the Tigers. The trio of Coleman, Hammink and Stringer notched 10 of the points. Andrew Del Piero, a former walk-on and tuba player in the Tiger Pep Band, also tallied four points and four rebounds during the spurt. He finished with eight points and five rebounds, both career highs.
LSU connected for a season-high 55.1 percent (27 of 49) compared to a 28.3 percent clip (17 of 60) from the floor for Mississippi Valley State (0-4).
The Delta Devils got within single digits to start the second half on two occasions -- the latest was 37-28 at the 15:45 mark.
LSU responded with 19 of the next 25 points over the next 6 minutes to seize control and go up 56-34 on a Stringer 3. The Tigers led by as many as 30, 71-41 with 4:12 remaining, after a Hammink trey.