No, it wasn’t the final sequence of “The Karate Kid” at the McDermott Athletic Center Saturday, but it looked like it as the North American Grappling Association (NAGA) hosted a jiu jitsu tournament. About 400 competitors ranging in age from 4 to 70-plus took to the mat in the all-day tournament with up to six matches running at a time. Nick Silcox, MAC general manager, said the organization rents out the facility several times a year, but this one was the biggest one as he expected to see 1,000 people come through the doors of the facility.