Shaking off Wallace's three first-half interceptions, the Rebels (1-0) got the victory before a sparse crowd in the Chick-fil-A Kickoff Game. But it was hardly the sort of convincing performance they were hoping for entering the season with their highest ranking since 2009.
Ole Miss led only 7-6 entering the fourth quarter before finishing off Boise State (0-1) when Wallace threw for TDs on three consecutive throws, ruining the debut of new Broncos coach Bryan Harsin.
Cody Core hauled in a pair of TDs: a 30-yarder in the final minute of the first quarter, then a 76-yarder midway through the fourth after grabbing a short pass on a slant route and breaking free down the middle of the field.
Also in the final period, Wallace went to Laquon Treadwell for a 14-yard TD and hooked up with Quincy Adeboyejo on a 31-yard scoring play.
That was more than enough against Boise State, which was coming off its worst season since 1998 (8-5) and seems to have lost its BCS-busting swagger. The Broncos had first-and-goal at the Ole Miss 1 in the second quarter, ran three straight plays that lost a total of 2 yards, and settled for a field goal. More telling, when still in the game and facing fourth-and-3 at the Rebels 40, they took a delay of game and punted the ball away.
For much of the night, neither team looked as if it was ready for the season. Wallace's three picks before halftime were matched by his Boise State counterpart, Grant Hedrick. For good measure, both QBs also had one picked off in the end zone, ruining good scoring chances.
But the poor play went beyond a bunch of errant throws.
Ole Miss was flagged for moving too soon on its first two attempts at getting off an offensive snap and wound up being called for a staggering seven false-start penalties in the first half. The Rebels couldn't blame the crowd for being too noisy, either. The upper deck at the Georgia Dome wasn't even used for a turnout announced at 32,823.
Boise State was even worse, hardly looking like the powerhouse that former coach Chris Petersen built before bolting for Washington after last season. Harsin, a former Broncos quarterback and offensive coordinator under Petersen during the glory days, watched his offense managed only a pair of field goals before a meaningless touchdown in the closing minutes.
Hedrick threw his fourth interception early in the fourth quarter, which pretty much finished off Boise State. Two plays later, Wallace found Adeboyejo open at the 10, and he easily broke away from a couple of would-be tacklers who did little more than stick out their arms.
Wallace finished 25 of 36 for 387 yards. Treadwell hauled in seven passes for 105 yards, while Core had 110 yards on four receptions.
Hedrick was 36 of 46 for 264 yards.