THE SIDELINES : Soviets Top Greece in Basketball

BUENOS AIRES —  Alexander Volkov keyed a 15-0 run midway through the second half and the Soviet Union beat Greece, 75-57, today in the opening game of the quarterfinal round of the World Basketball Championships.

Two free throws by Pano Giannakis with 10:04 to play brought Greece to within 51-49 before the Soviets put the game away with the decisive run, taking a 66-49 lead with 4:14 to play.

Volkov, who plays for the NBA Atlanta Hawks and is one of four Soviet players here from the gold-medal-winning team at the 1988 Olympics, scored on a driving layup and had a three-pointer during the run. Greece, which led 40-37 at halftime, managed just four field goals in the second half--two in the final minute of the game.

Greece was 14 for 43 from the field in the first half and four for 23 in the second half as it was frustrated by the Soviets’ tough man-to-man defense.

Volkov scored 23 points and had 15 rebounds and six assists to lead the Soviets, who play Yugoslavia on Tuesday in the second of three games in quarterfinal play. The top two teams from each group advance to Friday’s semifinals.

Giannakis, who shot five for 22 and missed all seven of his three-point attempts, led Greece with 22 points. Greece’s only qualifying-round loss was in overtime to the United States.