As the Trail Blazers strolled off the American Airlines Center court at halftime Wednesday, they bee-lined to the locker room with a four-point lead over the Dallas Mavericks on the scoreboard and a victory in motion.

There was just one problem: Coach Terry Stotts, the former Mavericks assistant coach, veered the wrong way, initially heading toward the Dallas locker room.

“Old habits,” Stotts said, sheepishly, explaining his mishap.

But it was an omen of things to come for the Blazers, who lost their shooting touch and lost their way at halftime en route to a 105-99 loss to the Mavericks before 19,746.

After seemingly hitting everything they threw up in the first half and matching the Mavericks punch for punch with a crisp and dynamic offense, the Blazers wilted in the second half, scoring just 38 points and shooting just 38.5 percent from the field. And they saved their worst for last.

The team that has played so clutch and looked so poised late in games for so much of the season was a fourth-quarter mess against Dallas, scoring just 17 points. The Blazers (25-24) managed just four over the first eight minutes, nine seconds as Dallas’ defense blitzed Portland point guards, doubled Blazers’ bigs and disrupted the flow and effectiveness of an offense that had made nine three-pointers and raced to 61 points in the first half.

“Both teams came in the locker room at halftime and said, We’ve got to tighten up our defense,'” Stotts said. “And I think both teams did.”