Fellow rookie Demontez Stitt had 13 points and five assists for the Tigers (8-0), who took control midway through the first half and never looked back.
Sam Hinnant scored 16 points to lead the Pirates (3-5), who led by three early before Clemson's defense locked down to fuel a 17-point spurt and help the Tigers build a big halftime lead.
East Carolina fell to 0-57 all-time against Atlantic Coast Conference teams, and faces another -- North Carolina State -- Saturday.
East Carolina's respect-starved fans were eager to see an ACC school come to Minges Coliseum for the first time in nearly four decades.
After all, the league -- particularly powers Duke and North Carolina located about 90 miles west -- have long hogged the spotlight while the Pirates have had to fight for any attention once basketball season arrives.
But the Tigers didn't allow much room for optimism once the game began. Despite playing again without injured forward James Mays (hip), Clemson pushed ahead for good with a stickback dunk and free throw from Raymond Sykes about seven minutes in before taking a 47-29 lead at the break.
Oglesby, who had nine points in the first half, kept the pressure on after halftime. After East Carolina had closed to within 14 midway through the half, he knocked down a 3-pointer to answer the Pirates' push. He then drained another one off a kickout to make it 60-39 with 12:14 left.
He hit his final 3 -- a straightaway shot from about five feet behind the arc -- to make it 67-44 with 91/2 minutes left. He finished 7-for-9 from the field and 6-for-7 from 3-point range, far above his season averages of 8.6 points and 31-percent shooting from long range.
Trevor Booker led Clemson with 17 rebounds.