The Jai Alai pelota is known as the most lethal ball in sports. It is 3/4 the size of a baseball and harder than a golf ball. The best in the sport can toss the pelota at speeds of over 300 km/h. As a result, Guinness World Records has dubbed Jai Alai as the fastest moving ball sport in the world. Squash – 281.6 km/h Although squash is played with a hollow rubber ball, the best in the sport can hit it at astounding speeds.