Grier completed 19-of-25 passes for 352 yards in two and a half quarters of action before giving way to backup Chris Chugunov with 4:18 remaining in the third quarter. Chugunov completed five-of-nine passes for 51 yards in his most extensive action as a Mountaineer
When Grier was in the game, the WVU offense operated like a well-oiled machine. All eight touchdown drives with Grier on the field were achieved in less than 2:20, with four coming under a minute.
ECU (0-2) deferred the opening kickoff and instead chose to give the ball to Grier, who marched West Virginia right down the field 75 yards in nine plays with Justin Crawford reaching pay dirt from the five.
Three of West Virginia's next four touchdowns came from Grier's arm, the former Florida transfer hooking up with Ka'Raun White for a seven-yard score, to Marcus Simms for a 52-yard TD and to Sills V for a nine-yard tally.
In between those touchdowns, sophomore tailback Kennedy McKoy scored on a sweep from the 13.
After its only unsuccessful offensive possession of the first half - a Mike Molina missed 44-yard field goal - WVU crossed ECU's goal line two more times. Crawford found a crease, broke to his right and out-ran the Pirate defense for a 41-yard touchdown and then Grier tossed a long pass down the far sideline to a wide-open Sills and he ran the remaining distance for a 75-yard touchdown.
The Grier-to-Sills pass play happened with only 30 seconds remaining in the first half to put the Mountaineers ahead by 46 points, 49-3.
East Carolina's lone score of the first half came on its second possession when Jake Verity punched in a 25-yard field goal.
Verity also hit a 45-yarder on ECU's first drive of the second half, culminating a seven-play, 79-yard march. The Pirates found the end zone five minutes later when Jimmy Williams beat the Mountaineer secondary for a 19-yard touchdown reception from Thomas Sirk.
Grier's final TD toss - a four-yarder to Sills with 6:07 left in the third quarter - put West Virginia ahead 56-13 and sent the quarterback to the showers.
The final quarter featuring mostly backups, consisted of dropped passes, missed tackles, penalties and one long Pirate touchdown when Trevon Brown beat WVU corner Corey Winfield down the far sideline for a 95-yard score on a high-arching pass from backup quarterback Gardner Minshew.
After the play an ECU assistant coach was penalized for unsportsmanlike conduct for going onto the field, which pretty much summed up the afternoon for Montgomery's winless team.
Crawford ran 15 times for 118 yards and two touchdowns to lead WVU's ground attack. It was his second straight 100-yard rushing performance for the Big 12's top returning rusher from a year ago following his 106-yard effort in the opener against Virginia Tech last Sunday. It was also his seventh career 100-yard effort.
Sills led the Mountaineer receiving corps with seven catches for 159 yards while Gary Jennings Jr., who led the team with 13 catches for 189 yards and a touchdown against Virginia Tech, was bracketed by the Pirate defense and finished the game with four catches for 46 yards.
Simms, returning to the field after a one-game suspension against Virginia Tech, caught the 52-yard touchdown pass from Grier and he also accounted for 83 yards in returns, including a 23-yard punt return in the second quarter that more than halved the team's 39-yard punt return total for 2016.
Eleven different players caught passes for West Virginia this afternoon.
The ground game finished with 216 yards.
Senior safety Ka'Raun White led the defense with a pair of interceptions - the first two turnovers the defense has come up with this season. Middle linebacker Al-Rasheed Benton once again led the defense with a team-best eight tackles, although the unit gave up 470 yards including seven-of-17 on third down.
ECU's two quarterbacks Sirk and Minshew combined to complete 23-of-47 passes for 328 yards and two touchdowns. Four different Pirate ball carriers combined to rush 32 times for 142 yards for a 4.4 yards-per-carry average.