NEW YORK — “Dear Evan Hansen,” the touching, heartfelt musical about young outsiders, has won the biggest theater popularity contest — winning the best new musical trophy at the Tony Awards along with five other statuettes, including best score, book and top actor honors for Ben Platt.

The show came into the night as the second-leading Tony nominee but ended up on top, with a revival of “Hello, Dolly!” starring Bette Midler next with four Tonys. “Oslo,” a three-hour meditation on diplomacy, was named best play.

Midler took the best actress trophy and — to the amusement and cheers of the audience — refused to be played off, forcing the swelling orchestra into silence.

“This has the ability to lift your spirits in these terrible, terrible times,” she said of her show.

“Dear Evan Hansen” came into the night behind “Natasha, Pierre & The Great Comet of 1812” with 12 nominations, but that musical which dramatizes a 70-page slice of Leo Tolstoy’s “War and Peace” stalled after winning just two technical awards, for best set and lighting.

Instead, the night belonged to “Dear Evan Hansen,” a show that centers on a profoundly lonely 17-year-old who fabricates a prior friendship with a classmate who has just committed suicide.

Platt thanked his cast mates, crew and family, calling his parents his heroes. He had this inspiring message to young people out there: “The things that make you strange are the things that make you powerful.”

Benj Pasek and Justin Paul, who recently won an Oscar for the song “City of Stars” from the movie “La La Land,” added to a remarkable year by earning Tonys for best score for writing the songs for “Dear Evan Hansen.”

Moments later, the show’s story writer, Steven Levenson, won the Tony for best book, and Alex Lacamoire earned one for best orchestrations.

Rachel Bay Jones won her first Tony for her work in the musical, capping a long career onstage with plenty of zigs and zags.

Cynthia Nixon won her second Tony, this time for her work in Lillian Hellman’s “The Little Foxes.” Nixon, the “Sex and the City” star, struck a defiant political tone, saluting those who refuse to stand by and watch bad things happen in the world.

Kevin Kline won his third Tony Award playing an egomaniacal matinee idol in the midst of personal turmoil in the play “Present Laughter.”