NEW YORK — Jalen Brunson scored 39 points, nearly extending his own franchise record for 40-point playoff games, and the New York Knicks routed the Atlanta Hawks 126-97 on Tuesday night for a 3-2 lead in the first-round playoff series.With their second straight lopsided victory, the Knicks positioned themselves to win the series Thursday night in Atlanta. They would have another chance at home in Game 7 if they need it — and it’s getting harder to picture why they should.The Hawks took a 2-1 lead in the series with one-point victories in Games 2 and 3, but a pretty sizable gap between the teams has appeared since. The Knicks led by 24 on their way to a 114-98 win in Game 4 in Atlanta and by 32 on Tuesday, when the lead was never below double digits in the second half.“I know they’re going to try to bring a lot of force down there,” Knicks reserve Jordan Clarkson said. “So we’ve got to be prepared and we know what’s coming, so we’ll be ready.”Brunson already had eight 40-point games in his first three postseasons with the Knicks. He hadn’t even cracked 30 in this series until pouring in 17 points in the fourth quarter to prevent any chance of Atlant …