Jamaal Franklin scored 15 of his 22 points in the first half to put No. 23 San Diego State up early, and James Rahon hit a key 3-pointer late in a 60-44 win over Missouri State.
The Aztecs led 39-30 midway through the second half before the Bears rallied. Missouri State (1-1) pulled within 41-37 on Anthony Downing's basket with 7:13 left.
But the Aztecs pulled away thanks to 3-pointers on consecutive possessions from Rahon and Chase Tapley.
It was the second consecutive victory for San Diego State since the Aztecs lost the season opener against Syracuse.
Franklin finished with a double-double with 10 rebounds.
Missouri State was led by Downing's 16 points. Keith Pickens, who missed the season opener to rest injured knees, had nine points and six rebounds.
The Aztecs, playing the equivalent of an 11 a.m. game West Coast time, appeared groggy much of the first half and then found themselves engaged in a defensive battle usually seen in the Bears' Missouri Valley Conference.
The Aztecs outrebounded the Bears 52-34.
Missouri State is in a rebuilding mode just two years after winning the MVC regular-season title, led by then-conference player of the year Kyle Weems, who graduated last season.