The Gladiators (17-6), who were runners-up in 2011, face William Campbell (20-5) Sunday at 10 a.m. in the championship.
Clymore started the game on the mound, but walked four batters in one inning before being relieved. Whitehead went the rest of the way, not giving up a hit until the seventh.
Cody Swisher had three hits, and Chance Staton and Logan Wolfe each drove in two runs for Riverheads.
Trailing 2-0 in the bottom of the second, the Greenwave loaded the bases with no outs and thought they had scored on a ground ball. But the runner was called for interference on a double-play attempt after sliding into second base and the run was nullified.
Dalton Dahley went the distance on the mound for the ’Wave, getting tagged for nine hits and five runs (four earned).
Clintwood, which won its first Lonesome Pine District tournament championship two weeks ago and followed that with Region D title, finished 20-5.