Danica Patrick will depart Stewart-Haas Racing at the end of the season after driving for five years with the team in the hugely popular NASCAR stock car series.
Patrick, 35, had one season left on her contract, but confirmed her departure on a Facebook post.
"It has been my honor to drive for Tony Stewart, Gene Haas and everyone at Stewart-Haas Racing," she wrote. "Together we earned a Daytona 500 pole, seven top-10 finishes and we also had some exciting racing along the way. My time driving for them, however, has come to an end due to a new sponsorship arrangement in 2018.
"... I wish SHR the best of luck with their new sponsorship and driver. Thanks for the memories. Right now, my focus is on the remainder of the 2017 season and finishing the year strong. I have the utmost faith in myself and those around me, and feel confident about my future."
Patrick, the only woman driver at NASCAR's top level, has endured a disappointing 2017 season and is 28th in the points standings.
She spent seven years in IndyCar before jumping to NASCAR.
Her victory in the 2008 Indy Japan 300 made her the lone woman to win an IndyCar race, and her third place finish in the 2009 Indianapolis 500 is the highest finish in America's premier race by a woman.
She's the only woman to win a top-flight NASCAR pole position, and while some in NASCAR have grumbled that the attention she garnered on the circuit outweighed her achievements at least one fellow-driver recognized her on Tuesday as a ground-breaker.
"Will likely take decades to see anyone even challenge her legacy," Brad Keselowski posted on Twitter. "NASCAR fans will miss her badly in time."