ATLANTA – Had to be Bama, didn’t it?

If Georgia’s run of terror was going to end, if its three-peat quest was going to fall short, of course Alabama had to be the one to stop the Bulldogs.

An old power restored its place on the SEC’s throne Saturday, when No. 8 Alabama stunned No. 1 Georgia 27-24 at Mercedes-Benz Stadium.

Nick Saban still runs this town, and Alabama once again rules this conference.

This SEC championship ranks as Saban’s most surprising. Georgia entered as a 5 1/2-point favorite and owned a 29-game winning streak. The last time we saw Alabama, it needed a fourth-and-31 completion to beat a mediocre Auburn team.

And the craziest part of this upset? As of this filing, Alabama’s spot in the College Football Playoff isn’t assured. A Week 2 home loss to Texas continues to tug on the Tide like a lead weight.

Greg Sankey worked the media circuit Saturday morning, lobbying for an SEC team to be considered an automatic for the playoff. Such politicking tells me the SEC’s commissioner doesn’t feel confident that the conference's spot in the final year of the four-team playoff format is automatic.

While the playoff field remains a topic for debate, here’s what’s not in dispute: Saban retains the keys to the Benz, like the Georgia Dome before it.

Alabama improved to 18-1 in games played in this city under Saban.

How did Alabama football upset Georgia? Defense and Jalen Milroe

Georgia marched 83 yards with precision on its opening drive. If you’d turned off your television after that scoring drive, you would have figured figured Georgia won by three touchdowns.

But Alabama’s star-studded defense woke up. The NFL draft will prove how many talented defenders Alabama possesses. Georgia's season-low 24 points also attests to it.

Georgia quarterback Carson Beck had been almost robotically reliable all season, but he had more difficulty finding open targets working against Alabama’s blanketing secondary. Multiple times, Alabama defensive backs nearly intercepted Beck. It never picked Beck off but settled for more incompletions than Beck normally throws.

Georgia had ranked among the nation’s best teams converting third downs, but even moving the chains on third-and-short became a chore against an Alabama unit intent on gang tackling.

Quarterback Jalen Milroe gave the Tide defense just enough support. Alabama’s first-year starting quarterback began the season as a liability. Now, he’s a cool customer, a clutch performer.

Milroe endured a rocky first quarter before sparking Alabama throughout a game-altering second quarter. Milroe’s rope toward the sideline to find a diving Isaiah Bond on fourth-and-4 became the game’s biggest completion. Alabama scored two plays later.

Like the Iron Bowl, Milroe did his best work with the game on the line.

With Alabama clinging to a three-point lead in the fourth quarter, Milroe calmly completed four straight completions on a crucial drive that resulted in an insurance touchdown. Later, Milroe used his legs to run out the clock.

Toast to Minnesota Gophers, and toast to Nick Saban's Alabama

The Bulldogs rarely beat themselves, but they contributed to their win streak ending Saturday. A penalty that backed up kicker Peyton Woodring 5 yards proved costly when Woodring’s 50-yard field goal clanked off the upright.

When Georgia lost a fumble inside the red zone, it gift-wrapped Alabama three points.

Alabama’s winning formula looked familiar to the height of Saban’s dynasty: Tough defense, no turnovers, limit mistakes and receive just enough clutch plays on offense.

I’ve said for a couple of years that I thought if Saban coached five more seasons, he’d win another national championship and add to his total of seven – but I didn’t think it would come this year. It still might not, but Alabama has become a more dangerous team than I ever thought it would just three months ago.

The offensive line matured. So did Milroe. Perimeter weapons emerged. And offensive coordinator Tommy Rees learned to play to Milroe’s strengths, which includes his running ability.

But, Alabama’s defense is foremostly responsible for this turnaround, and Saban’s decision to bring back a former sidekick, Kevin Steele, to run his defense paid off – never more than Saturday.

Someone should leave a glass of champagne and a cigar at the grave of Bernie Bierman. Georgia was trying to become the first team to three-peat since Bierman’s Minnesota Gophers achieved the feat in the 1930s.

Georgia’s aspirations of history appeared dashed after Milroe supplied his latest dose of fourth-quarter magic. He channeled Bryce Young when he bought himself time in the pocket and flicked a completion to move the chains on a third-down play during the fourth quarter.

Moments later, Alabama found the end zone, and “Sweet Home Alabama” played while fans chanted “Roll, Tide, Roll!”

Toast to Bierman’s Gophers, and toast to Saban’s Tide – once again, the SEC’s ruler.

Blake Toppmeyer is the USA TODAY Network's SEC Columnist. Email him at [email protected] and follow him on Twitter @btoppmeyer.