BOISE, Idaho (AP) -- Pressing, trapping and causing havoc, UAB's defense was at its frenetic best.

Yep, the Blazers could be ready for another deep run in the NCAA tournament.

Marvett McDonald had 21 points and hit five 3-pointers, and 11th-seeded Alabama-Birmingham used its stingy defense to pull off another upset, knocking off Louisiana State 82-68 on Thursday night in the first round of the NCAA tournament.

``Basically, they hadn't face pressure like we've given all year long,'' UAB's Donell Taylor said. ``They were kind of thinking we would come out a little weak and they'd be able to do what they want to do, but we got in those guys' grill and they were kicking the ball off their feet and throwing passes at each other's knees. We just stepped our defense up a whole lot more.''

They're doing it at just the right time.

UAB (22-10) reached the round of 16 last year after beating Washington and top-seeded Kentucky, and the Blazers seem to have that same kind of confidence after taking out the Chicago Regional's sixth seed.

Next up for UAB is third-seeded Arizona, which had trouble with No. 14 Utah State before pulling away in the second half for a 66-53 victory.

``What a defensive performance by our team,'' UAB coach Mike Anderson said. ``I thought our guys were clicking on a lot of different cylinders. We've been playing some pretty good basketball and now you're seeing some of the parts starting to come together.''

LSU (20-10) got into the NCAA tournament with an eight-game winning streak and a one-point overtime loss to Kentucky in the SEC title game, but the Tigers were no match for UAB's in-your-face defense.

LSU seemed to press once it fell behind and didn't find a rhythm offensively until it was too late, ending its first trip to the NCAA tournament since 2003 in disappointment.

``We just didn't handle it very well,'' LSU coach John Brady said. ``I really think some of those (turnovers) were unforced and we got tentative. Then when didn't make a couple of shot we would normally make I think a couple of our guys lost the confidence they had played with the last month or six weeks.''

UAB's attacking defense gave the Tigers fits from the start.

Using a seemingly endless bench -- all 12 players saw action in the first half -- the Blazers pressed the length of the floor and trapped in halfcourt sets, hounding LSU into mistakes and disrupting the flow of its offense. The Tigers had 21 turnovers -- 12 in the first half -- that led to 20 points, and had trouble controlling the ball even when UAB backed off, dribbling the ball off their feet out of bounds several times.

Carldell Johnson was particularly effective against Tack Minor, pestering LSU's point guard into seven turnovers, including two in LSU's first three possessions.

``We attacked Minor. He got cut off early in the game and when he didn't get a call, it kind of hurt their team,'' UAB's Demario Eddins said.

It sure did.

Afraid of having the ball swiped away, the Tigers had trouble getting the shots they wanted, settling for long 3-pointers and forcing up shots in the lane. LSU shot just 35 percent and was 6-of-31 on 3-pointers

Brandon Bass, the SEC's player of the year, led LSU with 25 points and 12 rebounds, but was the only player to hit more than half his shots (8-for-10). Darrel Mitchell, LSU's second-leading scorer at 13.5 points per game, had two points on 1-of-14 shooting and missed all nine of his attempts from long range.

``They're a scrappy team,'' Mitchell said. ``They made us turn the ball over a little bit and they got easy baskets off of it, and they capitalized on our turnovers.''

UAB's defense set up its quick-hit offense, leading to plenty of fast-break chances, spot-up 3-pointers and open looks before the Tigers were fully setup.

The Blazers led by as much as 14 in the first half, taking control with a 12-2 run midway through that put them up 26-15. UAB held LSU to 10-of-31 shooting in the first half for a 41-29 lead, and it only got worse for the Tigers to start the second.

LSU started off with -- surprise! -- a turnover and fell behind 59-34 after UAB opened with an 18-5 run in the first 6 minutes. LSU made a late run to cut UAB's lead to 75-66 with just over a minute left, but didn't have enough time to come all the way back.

``It's disappointing for me, for our players, that we really didn't show what kind of team we are,'' Brady said.