Matthews had 22 points in the first half. Terry, who coach Rick Carlisle sent in off the bench early, led the Mavs with 17.
"Our problems began at the beginning of the game when we got off to a very poor start and their aggressiveness put us on our heels," Carlisle said.
Terry's 3-pointer gave the Mavs a 57-54 lead, but both teams wrestled back-and-forth throughout the third quarter.
Portland went ahead 85-74 in the fourth after consecutive 3-pointers from Batum and Gerald Wallace.
"We hang our hat on defense," Terry said. "We gave up 95 points to this team, which we hadn't done in the first two games. That's the reason why we lost.
Dallas is 2-1 overall when it has opened a 2-0 lead in 15 previous best-of-7 series. The exception was the 2006 NBA finals, when the Miami Heat defeated the Mavericks in six games. The Heat were just the third team to claim a championship after trailing 0-2.
The last time Dallas and Portland met in the playoffs was 2003. The Mavs claimed the first three games before the Blazers won the next three. The Mavericks took the deciding game in Dallas.
NOTES: At the shootaround before Thursday's game, McMillan was asked what he told his team first thing that morning. "Win, baby. Win," was his reply. ... Matthews' four 3-pointers in the first quarter matched the team playoff record for a quarter, held by Terry Porter and Rudy Fernandez. ... Aldridge received the team's inaugural Maurice Lucas Award for the player that best represents the true spirit of Lucas, the former Blazers player and assistant coach who died in October after a battle with cancer. ... Dallas' Tyson Chandler fouled out with 7:24 left.
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