Indianapolis ? After watching the Boston Celtics wrestle inside and questioning their ability to fight, Doc Rivers changed tactics.

He used a small lineup Saturday to get the Indiana Pacers out of sync.

Brilliant move.

Paul Pierce finished with 30 points, seven rebounds, eight assists and five blocked shots, and Ricky Davis broke out of a shooting slump with 15 points to lead the Celtics to a 110-79 rout of the Pacers in Game 4, tying the first-round series.

“When we play good defense, we’re a good basketball team, no doubt about it,” Rivers said. “We pressured the ball and denied catches all game.”

It was just what the Celtics needed with the odds stacked against them.

Playing on the road without suspended Antoine Walker and facing the possibility of going two games down in the best-of-seven series, the Celtics refused to surrender.

Instead, they return to Boston for Game 5 having played one of their best games of the season.

Boston shot 56.8 percent from the field, 53.8 percent from three-point range, limited the dangerous-shooting Pacers to an NBA playoff record low of 26.9 percent from the field and handed Indiana its worst playoff loss since it joined the NBA in 1976-77.

The Boston celtics, from left, Gary Payton, Delonte West, Paul Pierce, Al Jefferson and Ricky Davis celebrate after Pierce was fouled while hitting a three-point shot in the fourth quarter. Pierce scored 30 points as Boston defeated Indiana in Game 4 of their first-round playoff series, 110-79, Saturday in Indianapolis.

Indiana’s worst previous defeat was 24 points to Orlando on June 4, 1995 in the seventh game of the Eastern Conference finals.

Only three Pacers scored in double figures — Stephen Jackson with 24, Reggie Miller with 12 and James Jones with 11.

Boston, in contrast, had all five starters score at least 11 points, led by Pierce, who shot 10-for-15 from the field and scored 23 points in the first half.

But it was the Celtics quick defenders that dominated the game.

“Their sheer athleticism really got us,” Pacers coach Rick Carlisle said. “They played this well without Walker. If they had played with Walker, it may have been worse, who knows.”

The Celtics spent Game 3 trying to rough up Pacers All-Star Jermaine O’Neal, which set off tempers. This time, Rivers started three guards and Pierce, a 6-foot-6 forward, to turn up the pressure on Indiana.

Carlisle expected it, but the Celtics made the strategy work.

“We said, ‘Lets treat this game like an elimination game,'” Pierce said. “We did, and now we’ve got the momentum back.”

Indiana’s biggest problem wasn’t only O’Neal’s sore right shoulder. It was foul trouble, poor shot selection and an offense that never dictated the tempo. The result: Indiana shot just 31 percent in the first half and was even worse in the second.