Northwestern State capped a season full of surprises by threatening to produce the biggest stunner of all.

The Lady Demons can only wonder what might have resulted if they'd hit a few more open shots.

Seeking to become only the second No. 16 seed to beat a No. 1 seed in the NCAA tournament, Northwestern State was tied with Tennessee early in the second half before the Lady Vols pulled away for an opening-round 70-46 victory.

"We didn't try to focus on what other people thought was a mismatch," Northwestern State forward Trudy Armstead said. "We just tried to come out and compete as much as possible."

The Lady Vols (28-5) won despite scoring just four points and making no baskets in the last eight minutes of the first half. Northwestern State (21-12) also struggled to shoot the ball and went just 3 of 19 from 3-point range.

Northwestern State had to deliver from the perimeter to have any chance at pulling the upset because of Tennessee's prohibitive size advantage. Tennessee outrebounded Northwestern State 47-27.

"I told them last night we weren't going to grow six inches overnight," Northwestern State co-coach Brooke Stoehr said.

Tennessee withstood an illness to head coach Holly Warlick, who said she came down with a stomach illness at about 2 a.m. Warlick said she initially feared she might not even be able to coach Saturday, but she made it to the game after undergoing IV treatments.

Warlick missed the team's morning shootaround. She joined her team for the game and sat on an orange stool during the first half while assistant coach Kyra Elzy stood and shouted instructions. Warlick stood throughout the second half and was much more animated as Tennessee gradually pulled away for its 14th win in its last 15 games.

"That was my choice, to sit in the first half," Warlick said. "I was still a little lightheaded. And then, I just couldn't sit there any longer."

Northwestern State (21-13), trying to become the first No. 16 seed to beat a No. 1 seed since Harvard stunned Stanford in 1998, forced a 22-22 tie early in the second half before the Lady Vols (28-5) scored 12 straight points to seize control.

After shooting just 22.6 percent (7 of 31) in the first half, Tennessee shot 58.1 percent (18 of 31) the rest of the way.

Isabelle Harrison, Meighan Simmons and Mercedes Russell each scored 12 points for Tennessee. Armstead had 12 points and Beatrice Attura had 11 for Northwestern State.

Tennessee, the only team to reach the tournament every year since the NCAA started running the event in 1982, improved its record in NCAA tournament home games to 53-0.

After making five of their first six shots to grab an 11-2 lead, the Lady Vols went 2 of 25 the rest of the first half and were clinging to a 22-20 lead at the intermission. Northwestern State stayed close despite shooting 8 of 28 in the first half.

"I went in the locker room, I'll be honest with you, and told them, 'Guys, I'm not happy being down two. You should be up five,' " Stoehr said. "We felt like we got some great looks."

Northwestern State never led Saturday, but the Lady Demons did tie the game 22-22 with 18:43 left on a basket by Janelle Perez, a guard generously listed as 5-foot-2. Stoehr said Perez actually is closer to 4-11. Her lack of height signified the long odds Northwestern State was facing against one of the nation's most storied programs.

"We have three kids in our starting lineup who did not have a single other Division I offer other than us," Stoehr said. "They just know their roles and compete very hard for us."

Northwestern State was making its first NCAA tournament appearance since 2007. The Lady Demons had gone 12-18 last season - its first under Brooke and Scott Stoehr - and were 6-23 two years ago.

Northwestern State won the Southland Conference tournament as the No. 4 seed after beating both Lamar and Stephen F. Austin, who shared the Southland's regular-season title.

Stoehr choked back tears as she described what this game meant to Northwestern State's program.

"When you believe in something and you buy into it, you can do a lot of good things," Stoehr said.