“They’re playing it in Boston,” Tom Petty drawled on Saturday, recalling what he was told in the wake of initially flat response to his Heartbreakers’ 1977 single “American Girl.” So Boston became one of his favorite cities to play, from the Paradise Rock Club to Fenway Park, where Petty & the Heartbreakers held court on Saturday, capping their two-hour set with the ringing chords and universal euphoria of “American Girl.”

In his decades-long career since recording that song, Petty has endured as a sort of garage-rocking Dylan, adopting Americana-shaded folk and jam-rock with a sly smile to offset the sneer. And he’s mostly done it with the Heartbreakers, a band that he called “the closest as I have to family,” still anchored by first-call session keyboardist Benmont Tench and now-dreadlocked lead guitarist Mike Campbell.

On Saturday, Campbell stood out with his unique tone, from his pinched cry in “A Woman in Love (It’s Not Me)” — following a lovely piano intro by Tench — to his sitar echoes in “Don’t Come Around Here No More.” But perhaps the comfort level that Campbell and Petty have honed over a 44-year-partnership was most evident when, rather than play different guitar models for ego-fueled contrast, they wielded matching vintage axes on the newer “I Should Have Known It” and outcast anthem “Refugee,” confident to complement each other as one.

The Heartbreakers came out kicking with the Byrds raveup “So You Want to Be a Rock ‘n’ Roll Star,” whose 12-string Rickenbacker sound also inspired the Florida-born, LA-based Petty. Not that the 63-year-old frontman acted much like a star, laconically pacing the no-frills stage in his jeans and suede boots with slow, sweeping hand gestures. He followed with “Mary Jane’s Last Dance,” its nod to marijuana sliding home when the song concluded and Petty asked the sprawling audience, “How are ya feeling?”

Fans were already feeling alright after opener Steve Winwood, who still sounded great at 66, focusing on his Traffic catalog in an hour set that also sported ’80s pop hit “Higher Love” and Spencer Davis Group gems, all driven by a grooving bass-free band. There was no letup as the singer switched between organ and guitar and fueled such classics as “The Low Spark of High Heeled Boys,” “Empty Pages,” “Dear Mr. Fantasy” and “Gimme Some Lovin,’” though it would have been nicer in a smaller space. Petty, by contrast, risked floating a mid-set, acoustic-tinged lull, though likely engaging diehards with deep tracks “Rebels” and “Angel Dream (No. 2).”

Nonetheless, Petty touched most of the bases (ha, another baseball cliché), even if a handful of nuggets like “Listen to Her Heart,” “Breakdown” and “You Got Lucky” went unplayed. You couldn’t blame the inclusion of three hearty tunes from the Heartbreakers’ chart-topping new Hypnotic Eye, peaking with the gritty “U Get Me High,” where the Heartbreakers dug into an AC/DC-like riff grounded by drummer Steve Ferrone, who Petty called the “greatest musician that I’ve ever met.” And so the family circle widened, with fans joining the clan to pipe the chorus to “Free Fallin’” as if they were hypnotized in a final salute to big summer concerts at the ballpark — though Jack White’s on deck for a smaller “Bleacher Theater” show on Sept. 17.