BASKETBALL—BOSTON increased its Eastern Division lead to five games by defeating the Lakers 108-98, the Royals 116-101, the Bullets 112-99 and the Celtics' two-time conquerors, the 76ers, 118-109 (60 fouls were called, 30 on each team). During the week Bill Russell grabbed the 14,000th rebound of his eight-year NBA career, scored his 10,000th point for the Celtics. Second-place CINCINNATI won two of three, and the Royals' Oscar Robertson, like Russell, made his 10,000th point, after only four years in the league. PHILADELPHIA lost two but came back to defeat the Bullets 102-97 and the Knicks 121-115. NEW YORK equaled its best streak this season by taking two straight, in between two losses. Western Division leader LOS ANGELES, lackluster without Elgin Baylor, who was sidelined with a muscle injury, dropped two of three. ST. LOUIS climbed to within 1� games of the Lakers by winning two of three but lost Bob Pettit because of a back injury. BALTIMORE extended its losing streak to five by dropping three more. DETROIT edged the Knicks 102-100 and the Warriors 104-100, but the Pistons were beaten three other times. SAN FRANCISCO'S fans had little to cheer about—there were too few, in any case, to make much noise (1,200 a game)—as the Warriors lost two. But they finally switched to team play (seven men scored in double figures) and had no trouble upsetting the Pistons 124-107.