And on the 12th day, the Minnesota State Fair gods said, "Let there be classic rock."

ZZ Top and Cheap Trick — the kind of 1970s-era, KQRS-FM-branded rock acts that for a long time were the bread and butter of State Fair concerts — hit the grandstand together Monday. And, not surprisingly, they proved a popular finale after a week and a half of country, pop, hip-hop, oldies and whatever Weird Al is. At least one of them proved to be far from stale, too.

Each of the Rock and Roll Hall of Fame groups was last seen in our area performing at casinos, where overpaying for such acts has made it hard for the fair to compete. With tickets priced just under $50 here, the Lil' Ol' Band from Texas and the Midwestern boys from Rockford, Ill., drew 11,352 fans for an impressive closing-night number at the grandstand.

Even more impressive, Monday's show was the latest in a steady string of Twin Cities gigs where Cheap Trick put both the headliner and many bands a third its age to shame.

Its singer hit the hard notes. Its set list was far from rote, with several older deep cuts and a couple worthy songs from the new millennium added to the mix. It actually jammed and improvised a little. And it actually looked like the fellas were having a blast.

None of those compliments could be paid to ZZ Top, but the three original members still got by on that unmistakably cool good-ol'-boy swagger of theirs, and on Billy Gibbons' still red-hot guitar styling.

Cheap Trick's relative surprises fueled the first half of its 65-minute set — including the 1978-1980 era nuggets"Downed," "Lookout" and "Baby Loves to Rock," along with the 2017 gem "Long Time Coming." The band stretched out further with a jammy take on the Velvet Underground's "Waiting for My Man" featuring bassist Tom Petersson on vocals.

The second half of the Trick's set was all hits, including"Dream Police," "The Flame," "I Want You to Want Me," "Surrender" and "The Flame," the latter where singer Robin Zander, 66, flexed his pipes like few rock singers his age can.

ZZ Top stuck to the nearly the same set list as last summer's outdoor gig at Treasure Island Resort & Casino. The start of the show and the encore were loaded with the band's bluesiest, dirt-road-gritty romps; tunes like"Waitin' for the Bus" and "La Grange" from way back when the trio actually scared a lot of people.

In between came the songs from the MTV era when people thought ZZ Top was rather cuddly, including "Gimme All Your Lovin'," "Sharp Dressed Man" and "Legs." The latter two came just before the encore and were uninventively accompanied by the original music videos played in full on the video-screen backdrop.

While bassist Dusty Hill sang a mean "Tush" to end the encore, Billy Gibbons, 69, sounded weak and muddy on the microphone through much of the set. He came through loud and clear on the guitar, though, especially when he uncoiled the rattlesnake-y solos in "Jesus Just Left Chicago" and "Just Got Paid."

Also just 65 minutes in length and done by 9:35 p.m., the Top's set ultimately seemed too much just like a payday, especially considering it was billed as the band's 50th anniversary gig.

"We've been coming at you for five decades," Gibbons proudly declared. "The same three guys, and the same three chords."

Alas, not all the band's sameness was to be celebrated.