ATHENS -- Whitehouse coach Brent Kelley had a tough decision to make when devising a scheme to handle Lancaster's offense. He ultimately decided to double-team the low post to make up for a severe size disadvantage, leaving perimeter shooters with open looks.

But Lancaster knew what to do from beyond the 3-point line.

Second-ranked Lancaster buried seven first-half 3-pointers to built a big lead, then coasted to an 84-64 win over Whitehouse on Tuesday night in their Class 4A Region II quarterfinal at Cardinal Gym.

The Tigers (30-4) will face fellow DFW Metroplex power Dallas South Oak Cliff at 6 p.m. Friday in one regional semifinal at Garland's Curtis Culwell Center. Whitehouse, which trailed by as many as 26 points in the second half, ended its season at 27-6.

Whitehouse's game plan early was to shut down Lancaster's duo of 6-9 forwards Elijah Thomas and Nate Morris, but that left the 3-point line largely unaccounted for, and Lancaster took advantage.

Five of the Tigers' seven first-half field goals from long range occurred in the second quarter, including Antwon Portley's buzzer-beater that sent Lancaster into the locker room with a 43-28 lead. It was Portley's third 3-pointer in the final 3:51 of the period.

"We had to stop the inside the game; that was our plan," Kelley said. "We knew they were going to get some open looks here and there. I've watched a lot of film, and that's the best I've seen them shoot it. You've got to give them credit."

Lancaster didn't hit a trey in the second half. The Tigers didn't need to, taking advantage of their superior size down the stretch and getting to the free-throw line 27 times over the final 16 minutes of play.

Thomas, a junior widely considered the best prospect in Texas in the 2015 class, finished with a double-double, collecting 19 points and 10 rebounds to go with a pair of blocks. His 6-9 partner in crime, Morris, added 11 points, seven boards, three assists and two blocks.

"We were just trying to make him go to his weak hand and trying to push him out away from the block," Kelley said of Thomas, who has offers from 20 major college programs, including Arizona, Baylor, Florida, Indiana, Kansas, Louisville, Ohio State and Texas, according to ESPN.com. "But he got a lot of it off rebounds. The big thing at halftime I told our guys is that when they did miss, we weren't getting the rebounds. When you've got two of those guys like that, it's tough to defend."

Kaelon Wilson led Lancaster with 20 points, while Portley finished with 17 points and four rebounds. Deondre Edwards was the fifth Tigers player in double figures with 10 points, six rebounds and two assists.

Whitehouse, which won the District 16-4A basketball championship after accomplishing the same feat in football last November, will lose all five starters -- Jaylon Dews, Patrick Mahomes, Jake Parker, Brady Hill and Spencer Shaw -- to graduation.

"It's a great group of kids -- kids that have had a lot of success in basketball and in other sports," said Kelley, who completed first season in Whitehouse after enjoying a successful five-year stint at Jacksonville. "They're just winners; they know how to win. I'm just fortunate to come be in the situation and coach them this year."

Shaw led Whitehouse on Tuesday with 20 points, which included four 3-pointers. Mahomes, coming off a monster 37-point, 10-rebound effort in the area round, finished with 17 points, 13 rebounds and three assists. Dews added 10 points and four assists, while Parker chipped in with nine points, six boards, two assists and two steals.

A Dews 3-pointer cut Lancaster's lead to 27-23 with 4:21 remaining in the second quarter, but that's when Portley and Tigers began to take over. Consecutive Portley 3's and a layup by Morris ballooned Lancaster's lead to 35-23 less than two minutes later.

Edwards' traditional 3-point play and Portley's buzzer-beat trifecta put an exclamation point on a dominant second quarter, in which Lancaster outscored Whitehouse 27-17 for a 15-point halftime lead.

"That was kinda the difference," Kelley said of Lancaster's 3-point shooting. "We were down 15 at halftime and lost by 20. That was the ballgame right there, that run they went on in the second quarter."

Whitehouse never got closer than 13 points in the second half, and a big reason for that was the Wildcats' struggles from free-throw line. Whitehouse was just 11-of-24 on the night, including 8-of-16 in the third and fourth quarters.

"We normally shoot about 72 percent from the line," Kelley said. "If we just shoot what we average, it's below 10 there in the fourth quarter. It would've been fun to see what would've happened."

No. 2 Lancaster 84, Whitehouse 64

Boys Class 4A Region II Quarterfinal

At Trinity Valley CC's Cardinal Gym, Athens

Lancaster             16   27   21   20   --   84
Whitehouse          11   17   16   20   --   64
LANCASTER (30-4) -- Kaelon Wilson, 20; Elijah Thomas, 19; Antwon Portley, 17; Nate Morris, 11; Deondre Edwards, 10; Robert Pride, 4; Dominique Fobbs, 3.
WHITEHOUSE (27-6) -- Spencer Shaw, 20; Patrick Mahomes, 17; Jaylon Dews, 10; Jake Parker, 9; Brady Hill, 4; Isaiah Clark, 2; Devon Miles, 2.
THREE-POINT GOALS -- Lancaster: Portley (3), Wilson (2), Fobbs, Thomas. Whitehouse: Shaw (4), Dews (2), Parker.