At this point, country star Kenny Chesney doesn’t really need to spice up his annual massive summer concert tour — thousands of Chesney devotees and tailgating enthusiasts will pack the football stadiums, either way. But this year, he threw in a twist that almost seemed like overkill, sharing the billing with his buddy Tim McGraw, another one of Nashville’s top reliable (and profitable) hitmakers.

And even though Sunday’s concert at FedEx Field was part of the pluralized Brothers of the Sun Tour, it was evident that, really, this was a Chesney show. After McGraw worked the stage for nearly 90 minutes of his most popular songs, Chesney burst onto a small platform in the middle of the stadium — and though the crowd was loud before, the atmosphere electrified as the thousands of people roared.

Beaming as he sang, Chesney hopped on a small chair contraption that transported him to the main stage, happily waving as he flew over everyone. The seemingly ageless Chesney, his trademark sleeveless shirt soaked in sweat by the fourth song, didn’t waste much time with small talk, because he knows what people want — his songs, lots of them, and ones that they already know how to sing. There are plenty to choose from: “Beer in Mexico,” “Summertime,” “Out Last Night,” “How Forever Feels,” an Uncle Kracker-less “When the Sun Goes Down” and the aching “Come Over,” which Chesney thanked the audience for making his most recent No. 1 single.

Chesney invited Grace Potter — of Grace Potter and the Nocturnals, one of the opening acts — to join him for “You and Tequila,” their steamy smash duet from last year. “This is slowly but surely becoming one of my favorite songs I’ve done in awhile,” Chesney admitted, as Potter crooned harmonies beside him.

Instead of the typical Chesney encore, McGraw appeared for a rendition of their duet “Feel Like a Rock Star,” which sounds like it was a created from a MadLib for a fist-pumping song to sing at a summer concert. Kicking off the jam session with a manly handshake, the duo segued into Chesney’s “She Thinks My Tractor’s Sexy,” going right into McGraw’s “Indian Outlaw” and wrapping things up with a cover of Jackson Browne’s “Running on Empty,” joined by openers Potter and Jake Owen.

McGraw, not used to being a warm-up act, kept the energy high as he went through a number of his hits: “Where the Green Grass Grows,” “Back When,” “Something Like That,” “Live Like You Were Dying.” Though the highlight of his set may have been when he stopped, mid-song, to personally kick out a rowdy fan. “Out. Out. Out of the stadium,” he barked into the microphone, pointing at the offending woman, as his puzzled band kept going with “I Like It, I Love It.”

Indeed, McGraw did show off more personality than his counterpart, telling the audience that it was his daughter Maggie’s 14th birthday, and wouldn’t everyone like to make her day with a quick serenade of “Happy Birthday”? Using his iPhone to capture the stadium crowd singing, the camera caught McGraw turning his phone around, filming himself saying, “Love you, baby. Happy birthday.”