The Terrapins (27-5), who won their eighth-straight game, got nine points from Wells in the final nine minutes and made just enough defensive stops down the stretch to put away the Hoosiers (20-13). They shot 7 of 8 from the free-throw line in the final 39 seconds to seal it.
Yogi Ferrell led Indiana with 18 points. Troy Williams scored 17 and grabbed nine rebounds. But Maryland limited the Hoosiers to a mere 36 percent to win the rubber match.
Maryland, meanwhile, is headed to the NCAAs for the first time in five years after making a strong transition from the ACC to the Big Ten. The Terrapins set a school record for regular-season victories with 26.
In a charged atmosphere, with fans from both sides trying to drown each other out, neither team would budge.
Maryland was leading 62-55 with 7:23 remaining after Jared Nickens nailed a three-pointer, delighting a boisterous Terrapins contingent, but the Hoosiers did not go away quietly.
Indiana was within 64-62 when Evan Smotrycz hit two free throws for Maryland. Two more foul shots by Wells after a defensive stop made it 68-62 with 1:18 remaining.
Ferrell answered with two free throws for Indiana, Jake Layman missed the front end of a one for Maryland, and the Hoosiers' Robert Johnson hit two more foul shots to make it 68-66 with 39 seconds left.
Indiana immediately fouled Smotrycz, who buried two more pressure-filled free throws to make it a four-point game, and the Terrapins made two more defensive stops to clinch the victory.
The Terps will face the winner of the Michigan State/Ohio State quarterfinal at approximately 3:30 p.m. EST tomorrow on CBS.