A little more than a year after almost single-handedly forcing American auto racing to confront the sport’s longstanding issues with racism, Darrell Wallace Jr., known as Bubba, became just the second Black winner in NASCAR’s top series, finishing first at a rain-shortened event at Talladega Superspeedway on Monday afternoon.

Wallace, 27, rose from relative obscurity to national prominence last year when he added his voice to the widespread national protest movement for racial justice and equality after the murder of George Floyd. It was not unusual to hear an athlete speak on the subject — but it was unusual to hear a NASCAR driver do so.

It was stirring for many, then, to see Wallace, NASCAR’s only current Black driver, wear an “I Can’t Breathe” shirt — referring to the last words of Floyd and of Eric Garner, who died in 2014 after a New York City police officer placed him in a prohibited chokehold — and display the slogan “Black Lives Matter” on his car last year. He spoke out about the racism he experienced on a daily basis as a Black man in an overwhelmingly white sport. His burst of activism, most notably, persuaded NASCAR to ban the display of Confederate flags, long a fixture at American auto races.

On Monday, Wallace had his biggest success on a racetrack, maneuvering to the front of the field five laps before the competition was ended by rain, with 104 of 188 laps complete. After the race, Wallace choked back tears when asked about his milestone.

“I never think about those things, but when you say it like that, it obviously brings a lot of emotion, a lot of joy, to my family, fans, friends,” Wallace said in a trackside television interview with NBC Sports. “It’s pretty damn cool.”

The only other Black driver to win at NASCAR’s top level was Wendell Scott, in 1963.

Wallace, who is in his first season racing for 23X1 Racing, the team owned by Denny Hamlin and Michael Jordan, was born in Alabama and raised in North Carolina. His mother is Black, and his father is white.

Wallace told The New York Times last year that, until recently, he had not spent much time pondering his place as a Black man in a predominantly white sport. That changed in 2020 after he watched the video of the killing of Ahmaud Arbery, a Black man who was shot while jogging in a mostly white neighborhood in Georgia. Wallace said he was stirred to think more deeply about the racial dynamics of his country and his sport — and, finally, to speak out.

On June 21 last year, a member of Wallace’s team reported finding a noose hanging in the driver’s garage stall at Talladega Superspeedway. The next day, in a show of solidarity, the other competitors and crew members at Talladega pushed Wallace’s car to the front of pit road before their race. The F.B.I., which investigated the incident, eventually concluded that the rope had been hanging in the garage since the year before and that Wallace was not the victim of a hate crime. NASCAR nevertheless announced that its employees would be required to undergo unconscious bias training.

Wallace had a far happier experience at Talladega on Monday afternoon.

Officials called off the event after the second rain delay of the afternoon. Wallace and his crew, who were waiting at his pit stand, erupted in shouts and celebration when the decision was made.

Wallace was joined on the podium for his victory photographs by his dog, a shepherd-poodle mix named Asher.

“You always got to stick true to your path and not let the nonsense get to you and stay strong, stay humble, stay hungry,” Wallace said after the race. “There’s been plenty of times when I wanted to give up. But you surround yourself with the right people, and it’s moments like this you appreciate.”