The Golden Gophers began their third season under Coach Tubby Smith and improved their record against non-conference teams during that span to 23-2.
Smith worked his 600th career game as a college head coach and improved his record to 430-170.
Rodney Williams scored 14 points for Minnesota, which reached the NCAA Tournament last year before losing to Texas in the opening round.
Tennessee Tech, winners of 12 games last season, was led by Kevin Murphy with 10 points. The Golden Eagles shot just 28 percent from the field and turned the ball over 27 times.
Minnesota closed the first half on a 9-1 run for a 37-22 lead at the break, then began the second period with a 14-6 outburst.