The Philadelphia Seventy-Sixers went a game up in their best-of-seven series with the Boston Celtics by topping the Celts 109-100 at the Boston Garden last night.

The Sixers never trailed in the game, though their lead was threatened many times. On top 56-45 at the half, Philadelphia increased its lead to as many as 15 points before a Boston rally led by John Havlicek and JoJo White diced it to only one late in the third quarter.

With less than eight minutes remaining Boston center Dave Cowens fouled out, and Philly one-on-oned its way to victory. Reserve guard Lloyed Free was particularly hyperactive in this stretch, netting eight of his 23 points, none from closer than 25 feet.

Julius Erving led the Sixers with 27 points, 15 coming in the first half, while Doug Collins and Free chipped in with 25 and 23, respectively. Havlicek paced the Celts with 25, while White had 19.