Competing with a presidential inauguration, multicity marches and big-budget Hollywood productions, M. Night Shyamalan’s creepy psychological thriller “Split” pulled off a surprising opening weekend victory, pulling in an estimated $40.2 million. The low-budget “Split,” which cost a reported $9 million to make, blew away predictions that it would be bested by Vin Diesel’s big, action-packed “xXx: Return of Xander Cage.”