Smith finished with 16 points and 12 rebounds. He and Durham, both freshmen, started the second half after combining for 19 points and seven rebounds in the opening 20 minutes.
Indiana worked over Howard's defense with passing and ball movement, something that didn't happen in Friday's season-opening loss to Indiana State.
The Hoosiers got the ball inside to DeRon Davis early, without reward. He missed his first five free-throw attempts before making his next two - to the roar of the crowd. His replacement, Freddie McSwain, missed his first two foul shots. Indiana (1-1) made just 12 of 29 from the free-throw line.
Then IU's youth delivered. Smith, Durham and sophomore Devonte Green combined for 19 of IU's first 21 points. The Hoosiers ended the first half on a 12-4 run for a 37-27 lead.
Juwan Morgan left the game after five minutes with a lower body injury and never returned.