By the time the thunder rolls, you’ve already been hit by the lightning.

The Auburn Tigers gave themselves a chance in the first half at Bryant-Denny Stadium on Saturday. No. 1 Alabama helped with a few mistakes — the Tigers hit on a couple of trick plays and even that most worrisome of omens for Alabama fans (at least those of the pre-Kick Six generation), the blocked punt. The Crimson Tide’s halftime lead was only three points.

Then the lightning struck.

Quarterback Tua Tagovailoa scorched Auburn for two touchdowns in just over five minutes and the Crimson Tide went on to a 52-21 victory that concludes its regular season at 12-0 and 8-0 in SEC play. In all, Tagovailoa was responsible for six touchdowns, five passing and one rushing,

“Tua doesn’t ever seem to get flustered,” Alabama coach Nick Saban said. “He always seems to respond exactly like you want a quarterback to respond.

“I don’t know why it was but there was not a lot of energy in the first half. In the second half, we scored quickly — boom, boom — and that changed the game.”

Both teams had good breaks and bad ones in the first half: Auburn had an apparent long touchdown run negated by a holding penalty, while Alabama had a third-down momentum-changing sack of Jarrett Stidham negated by a facemask call.

Tagovailoa had a rushing touchdown and a 4-yard touchdown pass to Henry Ruggs, but AU got a nine-yard scoring run from Anthony Schwartz and converted a blocked punt into a trick-play score, leaving Alabama with a 17-14 halftime lead.

The second half, however, was defined by the Tua Effect.

Even when Auburn hit on a go-for-broke deep ball for a 52-yard Stidham pass to Darius Slayton to cut the Alabama lead to 31-21 in the third quarter, it took just three plays — capped by a 40-yard scoring pass from Tagovailoa to DeVonta Smith — to cover the 75 yards that put AU away for good.

Tagovailoa added one more touchdown pass, a 22-yarder to Ruggs, who made a spectacularly athletic catch in the end zone. Jalen Hurts capped the five-touchdown half with a 53-yard touchdown pass, his only pass attempt, to Jaylen Waddle.

The Crimson Tide, which became the first team since the 1888 Yale Bulldogs to outscore its first 12 opponents by 20 points or more, will face Georgia in next week’s SEC Championship Game in Atlanta.

Reach Cecil Hurt at or 205-722-0225.