The Tigers (1-0) showed no signs of distress without coach Frank Haith, who started serving a five-game suspension levied by the NCAA last month.
Missouri won its 19th consecutive game at Mizzou Arena and hasn't lost to a non-conference opponent on its own floor since the 2005-06 opener. The team used 11-0 and 14-0 runs in the first half to break the game open.
JaMichael Hawkins led Southeastern Louisiana (0-1) with 14 points, while Jeffery Ricard added nine. Ricard and Dre Evans are the only returned starters for the Lions, who were picked to finish sixth out of 12 teams in the Southland Conference.
Missouri interim head coach Tim Fuller said this week he couldn't sleep Tuesday night after Haith told him he would be taking over. Fuller, who had no previous head coaching experience, paced the length of his bench throughout the night despite his team never being in danger.
Earnest Ross opened the game with consecutive 3-pointers to give the Tigers a lead they would never relinquish. He then assisted on a layup by Johnathan Williams III, who became the first freshman to start a season opener for the Tigers since 2004.
Brown is the Tigers' lone returning starter from a 23-11 campaign last season. The team lost more than 60 percent of its scoring, rebounding, assists and steals, much of which left when Phil Pressey decided to forego his senior season and join the NBA.
Ricard's 3-pointer with 7:06 remaining in the first half broke up Missouri's big runs, but the Lions shot just 26 percent from the floor before the break and didn't reach the free throw line. They did score the final five points in the half, capped by a thunderous alley-oop dunk by Devonte Upson fromHawkins with 43 seconds left.
Coach Jim Yarbrough said this week he hoped to see some consistency with his squad as it welcomes four junior college transfers and three freshmen. But other than an 8-0 run capped by Ricard's traditional three-point play 15 seconds into the second half, Southeastern Louisiana struggled to establish any rhythm against the Tigers.
A crowd of 7,926 watched the Tigers shoot 54.4 percent from the field but only 55.6 percent from the charity stripe. A 12-1 run that ended with a free throw by Brown gave Missouri a 72-33 lead with 8:22 remaining in the game. The teams then traded baskets until the final buzzer.