Paul Pierce was stellar for Boston.Just maybe all the talk about how old and decrepit the Boston Celtics are actually does inspire the crafty veterans. For, again, just when they looked too slow to keep pace with the younger, more athletic Philadelphia 76ers, they rallied around their savvy and experience and clobbered them Wednesday night.Sixteen-year veteran Kevin Garnett had 27 points and 13 rebounds as Boston made mince meat out of the Sixers, pounding them 107-91 in Game 3 of their Eastern Conference semifinals series. The Celtics recaptured the home-court advantage, leading the series now 2-1.”We just wanted to come out and establish who we are as a team,” said all-star forward Paul Pierce, who scored 24 points, 13 rebounds and back-to-back power dunks, despite playing on a creaky knee.Coach Doc Rivers said point guard Rajon Rondo established a victorious mindset at the morning shootaround, hours before the game. Rondo was focus and serious, and it carried over to his play. He had 23 points and 14 assists (and just one turnover).Garnett scored 13 of Boston’s 32 points in the second quarter as the Celtics gained separation. The first two games were each decided by one point. Not Wednesday. Garnett assured Boston would have an easy time of the Sixers, who just seemed overwhelmed by Boston’s execution and determination.Philadelphia got outrebounded by 11 and shot just 40 per cent from the floor. They get a chance to even the series in Game 4 on Friday.