The Philadelphia 76ers combined the hot shooting of Lionel Hollins and a tenacious defense yesterday to roll over the Boston Celtics, 105-94, for the National Basketball Association's Eastern Conference championship.

In defeating the Celtics in Boston for the second time, the 76ers captured the best-of-seven series, 4-1, advancing to the NBA championship round against the winner of the Western Conference series between Los Angeles and Seattle.

Hollins, a veteran guard acquired from Portland in midseason, scored 24 points, including 15 in the first half as the 76ers built a 58-52 advantage.

The Celtics, unable to penetrate the tough Philadelphia defense once again, were unable to get closer than four points the rest of the way. Boston lost three games in a row for the first time this season in bowing out of the playoffs.

The Celtics couldn't get any momentum going, falling behind, 83-73, after three periods and by as much as 19 points midway through the finale.

Philadelphia superstar Julius Erving scored only 14 points. But the Celtics' big gun, Larry Bird, collected only 12 in winding up his rookie year.

The 76ers got a big boost from their bench as Bobby Jones hit for 19 points, including nine in the second period. Reserve forward Steve Mix also added eight in the second quarter surge.