Chuck Harris and Matt Cross both scored 12 points and SMU had a successful debut in the Atlantic Coast Conference tournament, defeating Syracuse 73-53 in Wednesday night’s second-round game in Charlotte.SMU’s defense did most of the good work as Syracuse, which had a season-low point total, couldn’t get untracked in the second half.Boopie Miller and Keon Ambrose-Hylton each contributed 10 points for the Mustangs, who are in their first season in the ACC.SMU needs to string together victories to get into position for an NCAA Tournament bid and this was a good start, beating the Orange for the second week in a row. The sixth-seeded Mustangs (23-9) meet third-seeded Clemson (26-5) in Thursday’s late-night quarterfinal.J.J. Starling scored 11 of his 16 points in the first half for 14th-seeded Syracuse (14-19). Jyare Davis added 14 points and Eddie Lampkin Jr. had 10 rebounds, but the Orange have never won more than one game in the ACC tournament since joining in 2013-14.The Orange’s 34 percent shooting from the floor and 15 turnovers were too much to overcome, so Adrian Autry’s second season as coach came to a close.Syracuse, which shot 8-for-30 in the second half, didn’t score for the first 5 1/2 minutes after halftime. By then, SMU had built a 41-28 lead.