Cory Cox added 57 yards rushing on just four carries and a 9-yard touchdown run for the Cavaliers (10-1) while Josh Martin was on the receiving end of both of Boatwright's completions for 59 yards and a score.
The Greenbrier West defense also did the job, creating seven Meadow Bridge turnovers, including two interceptions for Parker.
Meadow Bridge's Jake Parker ran for a game-high 194 yards on 38 carries, including a 22-yard touchdown. The Wildcats (8-3) managed just 201 yards of total offense.
The Cavaliers will travel to Point Pleasant to take on No. 3 Wahama next week.
Cox had touchdown runs of 10, 69 and 4 yards to pace RCB (10-1) in its first playoff game as a Class AA school.
Jacob Yanero led Braxton County (6-5) with 152 rushing yards and a touchdown on 23 carries. Yanero also threw for a touchdown, connecting with Derek Barnette for a 30-yard score.
Loftus added 61 yards on six carries for the Skyhawks (8-3), who forced five turnovers against the Warriors (7-4).
Scott's Cody Brown completed 5 of 11 passes for 85 yards and one TD, a 29-yard hookup with Michael Belcher (five catches, 57 yards). Tyler Jude also threw a 37-yard scoring pass to Dylan Dehart.
For East, Jacob Dulcie ran seven times for 74 yards.
For Keyser (10-1), Danny Fife rushed for three TDs, while Hunter Kasmier, who ran the ball all of 19 times in the regular season, tallied 175 yards and two TDs on 16 carries.
For Mingo Central (5-6), Joseph Hall had an 80-yard rushing score. Joe May, the team's 1,000-yard rusher, was held to minus-1 yard on eight carries.
Donte Hendricks also ran for two scores for the Highlanders (9-2), who led 42-13 at halftime. Mark Shaver threw for one TD and ran for another.
For Elkins (7-4), L.J. Lawrence carried 12 times for 180 yards and two TDs covering 72 and 60 yards and Clayton Collett returned a kickoff 77 yards for a score.