The Canucks kept it close until Paille scored on a breakaway late in the second period, then Boston controlled the final 20 minutes for its sixth win in seven games.
"We've been in a pretty good stretch. We've had a goal leading up until the Olympic break to try and go in the right way," Iginla said. "We have two left, then some of the guys will go and we'll enjoy watching them."
Vancouver had won the last two meetings since the Bruins beat the Canucks in seven games in the 2011 Stanley Cup finals.
Boston appeared to take a 3-1 lead just 2:21 after Diaz scored, but Brad Marchand's goal was waved off after officials ruled Boston's Torey Krug interfered with Luongo. The goalie immediately protested and gave Krug a shove, which led to a crowd in front of the net but nothing further.
Luongo had no argument after the next goal. Paille took a long pass from Johnny Boychuk at the blue line for a breakaway and beat Luongo on a backhand with 2:54 left in the period.
Rask stopped a pair of short-handed chances during Boston's first power play, then Daniel Sedin's breakaway in the second that led to the Bruins' second goal. Zdeno Chara slipped a crossing pass to Iginla for a one-timer past Luongo on the glove side with 12:01 left in the second.
Lucic, who gave Boston a 1-0 lead 5:12 into the game, also got an assist on the play.
NOTES: Iginla's assist on Lucic's goal was the 600th of his career. ... Diaz made his Vancouver debut after he was obtained from Montreal for forward Dale Weise on Monday. ... The Bruins improved to 27-3-0 when leading by two or more goals this season. ... Chara played his final game for the Bruins before leaving for Russia to carry Slovakia's flag during the opening ceremony at the Winter Olympics on Friday.