NEW YORK—Freshman Trevor Keels scored 25 points and classmate Paolo Banchero added 22 to help No. 9 Duke open Mike Krzyzewski’s final season by beating 10th-ranked Kentucky 79–71 on Tuesday night in the nightcap of the Champions Classic. Krzyzewski announced that he would retire at the end of the season. The Hall of Famer has won 1,098 games and five national championships in his 42 years coaching the Blue Devils. Overall he has 1,171 wins, the most in the history of the sport. The two basketball blue bloods, who have quite the history between them on the game’s biggest stage, put on a spectacular show to open the season. The loud split crowd at Madison Square Garden that included many members of the New York Knicks and Bruce Springsteen was on its feet for most of the second half. Duke, which led by four at the half, built the advantage …