PORTLAND, Ore. – Maybe it was post-clinch depression.

Or maybe the Mavericks just had too many players missing. Whatever the reason, they were guilty of a deplorable first half – their first stinker in more than two weeks – and couldn't see a rally through to completion, getting upended, 108-105, by the Portland Trail Blazers on Saturday at the Rose Garden.

The Mavericks clinched a playoff berth Thursday. Good thing, because they didn't look like a team that was sharpening an edge for the postseason, at least not for the first three quarters.

"We weren't in a good state of mind early in the game," coach Avery Johnson said. "They made every single shot. The ones that we were contesting, they still made them. We couldn't get stops when we needed to."

The Blazers had a 64-point first half and shot 64 percent. The Mavs thought they were going to see a Portland team that had gone down meekly at Sacramento on Friday night. Instead, they got hit with a torrid team.

Dallas kept hold of the No. 7 seed in the playoff race since Denver also lost and will be the seventh seed unless it loses its last two and the Nuggets win their last two.

But figuring out the Mavs' first-round opponent got even tougher. New Orleans, San Antonio, Houston and the Los Angeles Lakers all have 25 losses at the top of the Western Conference.

The Mavericks have to hope Saturday night was a hiccup and not the start of a late-season swoon. They may have had a human-nature letdown after clinching their playoff berth Thursday.

"You try to fight against it," Johnson said. "We don't want to go into the playoffs starting off the first quarter like we did tonight. We won't be able to beat anybody.

"But we're not going to drop our heads about this loss."

The Mavericks were sluggish early on, and that might have been an insult to slugs everywhere. They also were shorthanded, missing Josh Howard and Jerry Stackhouse. Howard may return for tonight's game at Seattle, but Stackhouse said after the Portland game that he is eyeing a return Wednesday.

AP

Dallas Mavericks forward Dirk Nowitzki defends as Portland's Jarrett Jack (1) drives to the basket.

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Dirk Nowitzki, who had 28 points, threw in two jumpers, the second making it 101-101 with 58.7 seconds to go.

But Brandon Roy dished to former Seagoville and Texas Longhorns standout LaMarcus Aldridge for a dunk that turned into a three-point play when he was fouled by Jason Terry with 49.4 left.

Terry hit two free throws, leaving the Blazers up by a point. But a wide-open 14-footer by Travis Outlaw with 28.5 seconds left restored Portland's lead to three.

The teams matched free throws and the Mavericks had one last gasp to force overtime, but Terry missed a layup while trying to draw a foul, then was off the mark on a 3-pointer at the buzzer.

"Three the hard way," Terry said. "It just didn't happen. It is what it is. They got us."