The win is the Chanticleers' (9-9, 4-3) first against Campbell since Dec. 20, 2003.
Raffa scored 20 points and Greenwood 18 for Coastal Carolina, which shot 49 percent (24 of 49) and made 22 of 31 free throws.
The Camels entered having won seven of their past eight games with a 48.6 shooting percentage. Saturday, Campbell hit just 37.5 percent (21 of 56), and Trey Freeman, who was averaging 16.6 points per game during the run, had just two points on 1-of-11 shooting.
Coastal Carolina snapped a 22-22 tie with a seven-point run to close out the first half, then scored the first six of the second half for a 35-22 lead.
Maryland point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.