Leading 10-6, the Phoenix (2-2) outscored the Tigers (2-1), a Division III team, 14-3 to lead 24-9 with 11:30 remaining until halftime.
It was 40-19 by halftime, as Elon outrebounded Hampden-Sydney 31-18 and scored 14 second-chance points in the opening 20 minutes. The Phoenix continued to pull away, scoring 14 of the first 18 points in the second half.
Long and Roger Dugas each grabbed eight rebounds for Elon, and Jack Isenbarger had a career-high eight assists. Long also had four assists, leaving the senior seven from moving into third place on the school's career list.
Ru White led Hampden-Sydney with 19 points. He made 8 of 13 shots; the rest of the Tigers shot 15 of 50.
Northwestern has never made the NCAA tournament, but the Wildcats' upward trajectory suggests 2016-17 could finally be the season it happens.
Dillon Brooks, who led Oregon with 16.7 points per game last season, will opt out of the NBA draft process and return to the Ducks, a source told ESPN.
Mississippi State freshman guard Malik Newman will withdraw from the NBA draft, but sources told ESPN he might explore other opportunities besides returning to Mississippi State.