EVANSTON—Mississippi Valley junior transfer Davon Usher scored a game-leading 35 points to almost single-handedly keep the Delta Devils in the game, but Northwestern got key late baskets from sophomore guard Dave Sobolewski to pull out an 81-68 win on Thursday night.Sobolewski scored his first field goal of the season on a layup to break a 58-58 tie midway through the second half moments after Usher had hit a 3-point shot from the right corner to knot the score.Sobolewski scored all 13 of his points, including two 3-point baskets, down the stretch to give Northwestern (2-0) the victory.Reggie Hearn had 23 points and Jared Swopshire added 22 for the Wildcats, who needed a 23-10 spurt in the final 8:54 to win.Usher seemed to zone in as the game progressed, going 7 of 8 on 3-point attempts He had scored 32 points in his first two games with Mississippi Valley (0-3).