Robertson hit 5 of 10 from 3-point range for Chattanooga (11-2), which has won six in a row and is off to its best start since the 1993-94 season. Dee Oldham scored 11 points with nine rebounds and Tre' McLean added 10 points.
Oldham hit a 3 and converted a 3-point play during a 14-3 stretch that closed the first half and gave Chattanooga a 40-29 lead at the break.
The Mocs pushed their lead to as many as 29 points as Lipscomb (4-12) shot just 29 percent, including 3 of 18 from 3-point range, in the second half.
Brett Wishon led the Bisons with 14 points.