Boxer Christy Martin had one big tip for Sydney Sweeney

Over a 24-year career in the boxing ring, Christy Martin became one of the best female fighters in the world — a Hall of Famer and super welterweight champion who fought 59 times and won 49, the majority by knockout.

Over a 24-year career in the boxing ring, Christy Martin became one of the best female fighters in the world — a Hall of Famer and super welterweight champion who fought 59 times and won 49, the majority by knockout. She was promoted by the legendary Don King, arguably the most bombastic personality in a sport full of them. Martin competed on cards headlined by Mike Tyson, Evander Holyfield and Julio César Chávez.

It takes a lot to impress her. But seeing Sydney Sweeney portray her in “Christy” — which debuted in theaters on Friday — Martin said she was at a loss for words.

“If you see anybody do that, it’s one thing. But you see Sydney Sweeney doing that? It was a whole ’nother level of ‘wow,’” Martin told NBC News in a recent interview conducted over Zoom. “She’s the ‘it’ girl. She’s the hottest thing right now in Hollywood. She got down and dirty and became a professional fighter.”

But this wasn’t Sweeney’s first experience in the combat sports world. For most of her teenage life, she was a kickboxer and grappler.

“I started when I was 12, and I trained up until I was 19 [or] 20, so I’d been hit before,” Sweeney told NBC News. “I’ve been choked out. I’ve been stuck in triangles that I can’t get out of. So I kind of already had that background with me. But being able to jump back into it and do it back home with my whole family there, watching me and cheering me on, was just a great experience.”