As far as biographical plays go, Arena Stage’s winning production of “Toni Stone” is more of a curveball on the outside corner than a fastball down the middle.

Lydia R. Diamond’s fact-based account — about the first woman to play full-time professional baseball in the Negro Leagues, with the Indianapolis Clowns in the 1950s — exists in a nebulous storytelling space, where the fourth wall has been shattered and side characters linger in Stone’s memory like a Greek chorus. As Stone informs the audience, she’s not one to tell her story “all nice and neat.”

After running off-Broadway in 2019, and seeing its spring 2020 run at Arena Stage postponed because of the coronavirus pandemic, “Toni Stone” is batting leadoff for the arts center’s comeback season as D.C. theaters ramp up indoor, in-person performances. At Thursday’s opening night, as patrons were asked to flash their vaccination cards before entering and ushers patrolled the aisles with “Masks on, phones off” signs, there was no mistaking the experience for business as usual. But, sure enough, the artistic illusion took hold all the same.

Even when Diamond’s script bites off more than it can chew, its vibrant realization of Stone as an amusingly unassuming trailblazer — and Santoya Fields’s effortlessly appealing lead performance — compensates. Prideful but endearingly innocent, the underappreciated pioneer is presented as a numbers-obsessed prodigy decades before Bill James coined the term “sabermetrics.” By letting Stone’s origins unfold via flashback, Diamond slides right into the day-to-day grind of life on the Negro Leagues circuit, where the travel is grueling, the dugout banter flies, showmanship trumps championships and bigotry looms.

Cautioning that “you don’t have to try and remember their names,” Stone promptly introduces the audience to the rest of the Clowns’ lineup, as inhabited by eight impeccable performers also playing countless other characters in Stone’s story. As Alberga, the smooth-talking tavern owner who takes a shine to Stone, Aldo Billingslea exudes a casual charm. Kenn E. Head steals scenes as both Willie, a stumbling drunk with a knack for timely hitting, and Millie, the crassly comic prostitute who lets Stone and her teammates crash at her brothel. Gilbert Lewis Bailey II stands out as Spec, the Clowns’ W.E.B. Dubois-espousing bookworm and etymology expert. And Sean-Maurice Lynch is sumptuously smarmy as the Clowns’ owner, Syd Pollock.

When it comes to depicting baseball itself, director Pam MacKinnon and choreographer Camille A. Brown artfully channel the game’s idiosyncratic rhythms with nary a ball in sight. Diamond, meanwhile, finds America’s favorite pastime to be ripe for life lessons and elegiac analogies. Riccardo Hernández’s set, featuring stadium lights and three sets of bleachers, is smartly minimalist.

“Toni Stone’s” only flaw is one of overambition; inevitably, a play packed with myriad characters and ideas can’t find a way to fully service them all. A bold sequence at the end of Act 1, which evokes Jackie Sibblies Drury’s “Fairview” by examining how White audiences judge Black artistry, deserves further exploration that Act 2 doesn’t deliver. Instead, much of the play’s climactic conflict is centered on a jarring turn for a supporting character whose arc largely occurs offstage. The poignant question of how Stone retains her independence when everyone wants a piece of her is answered a bit too abruptly, as well.

Yet the marriage of Fields’s commanding performance with Diamond’s vivid characterization still makes Stone a star worth rooting for. Fields’s subtle expressions of pain and perseverance should be particularly moving when the production gets a free simulcast on the Nationals Park jumbotron Sept. 26. And such a grand venue will be apt: By swapping the typical nonfiction formula for an anecdotal and abstract slice-of-life portrait, “Toni Stone” takes some big swings — and connects more often than not.

Toni Stone, by Lydia R. Diamond. Directed by Pam MacKinnon. Choreography, Camille A. Brown; set, Riccardo Hernández; costumes, Dede Ayite; lighting, Allen Lee Hughes; sound and music, Broken Chord. With Deimoni Brewington, JaBen Early, Rodney Earl Jackson Jr. and Jarrod Mims Smith. 140 minutes. $56-$95. Through Oct. 3.