Kurt Thomas, who became the first US athlete to win a gymnastics gold medal at the world championships, died Friday. He was 64 and died from complications caused by a basilar stroke last month.

Wife Beckie Thomas confirmed the news to International Gymnast Magazine. “Yesterday I lost my universe, my best friend and my soul mate of 24 years. Kurt lived his life to the extreme, and I will be forever honored to be his wife.”

Thomas competed in the 1976 Summer Olympics, then won a gold medal at the 1978 world championships for his work during the floor exercise. He followed that by winning a record six gold medals at the 1979 world championships, a record since tied by Simone Biles, who matched it at the 2018 world championships.
He entered 1980 as a strong favorite for a gold medal at that year’s Olympics, but was denied a chance when the US boycotted the games. By 1992, his attempt to rejoin the Olympics was thwarted by up-and-comers, and Thomas didn’t advance past the trials. Thomas was a five-time NCAA champion at Indiana State University, and was part of the 1977 national championship team. He was inducted into the International Gymnastics Hall of Fame in 2003.

As his gymnastics career waned, Thomas turned to Hollywood. He started in the film Gymkata in 1985, the story of an American gymnast who travels to a foreign country to compete in a deadly game not won by anyone other than a native in more than 900 years. He later had roles in the films Slam and Circus.

Olympic gold medalists Bart Conner paid tribute to Thomas on Twitter, calling Thomas a “cherished friend.”

“Kurt Thomas was a fierce rival, who went on to become a cherished friend. Proud to have been your teammate! Sending hugs to his wife Beckie, his children, Hunter, Kassidy and Kurt, as well as the entire gymnastics community, who lost a true pioneer today.