Beaumont and Troutman combined to shoot 72.2 percent (13 of 18) from the field. Sebastian Koch contributed 16 points, hitting 10 of 12 from the line -- 5 of 6 in overtime -- for the Phoenix (18-8, 11-3), who have won three straight and 10 of 11.
The Catamounts led 64-61 with 2:11 left in regulation on Tankelewicz's 3-pointer. Troutman hit 1 of 2 foul shots and Jack Isenbarger hit both of his to tie it.
Catamount Josh Mendenhall's layup tied it at 69-all with 2:21 remaining in overtime, but Elon ran off seven straight points to secure the victory.
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point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.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.