The Lady Hilltoppers' 19-25, 25-11, 25-15, 25-18 win came a couple hours after they swept David Crockett, 3-0.
Thomas had 14 kills and four blocks and Gay finished with 12 kills and three blocks in the Science Hill win.
"We've always been beside each other since freshman year, and we've developed that chemistry," Thomas said. "All the adrenaline just kept going and going. Once we did something good, it was a waterfall effect."
Gay added, "It was a sweet win. We lost to them both times during the season. It feels good."
The Lady 'Toppers got 26 assists and four aces from Alyssa Neal. Jesse Franks had five kills and 13 digs, with Riley Layton with five kills and 10 digs. Attie Forbes added five kills in the offensive attack and Meghan Carroll had 14 digs.
"We've been working on a quick offense, firing on all cylinders and having multiple players available to swing. We did that tonight," Science Hill coach Laura Cook said.
Greyson Stevens had seven kills and 10 digs to lead the Lady 'Blazers. Jaycie Jenkins had three kills and 10 digs, while Abby Herbert collected six kills and Dannah Persinger produced three blocks. McKenna Dietz finished with 19 assists. They struck first before the momentum shifted.
"Science Hill has been playing aggressive lately and we came out prepared for that," Boone coach Chelsea Spivey said. "Then, we got comfortable and didn't keep playing. We didn't do a good job reading and covering the block."
Science Hill will play Dobyns-Bennett in a Wednesday winner's bracket match at 5:30 p.m. to be followed by an elimination game between Daniel Boone and Tennessee High.
Dobyns-Bennett 3, Tennessee High 0
The Lady Indians (32-3) wanted to make quick work of the Lady Vikings and they proceeded to do just that in a 25-15, 25-14, 25-20 victory.
Hannah Watson led the way with 15 kills and four blocks. Courtney Whitson finished with 10 kills, while Staley Humphries continued to perform at a high level with eight kills and 14 digs. Caroline Cable added seven kills.
"Our two horses in the front row, Courtney Whitson and Hannah Watson, and then Staley and Caroline did a good job where nobody knew where the ball was going," Dobyns-Bennett coach Megan Devine said. "That puts it back in our passers' hands and to our setter, who has done a great job all season."
The setter, Riley Waye, had 42 assists, while Chloe Harless had 25 digs and two aces. Other leaders included Carly Shell with 17 digs and Zoie Larkins with nine digs and two aces. The Lady Indians stayed in control other than being tied with Tennessee High in the middle of the third set.
"For the most part, our team was consistent starting and finishing strong. It's just the middle points we need to clean up a little," Devine said. "They had the mindset tonight that we wanted to get in and get out because if we play our game, no one can beat us."
Science Hill 3, David Crockett 0
Claire Thomas had eight kills and Alyssa Neal finished with 12 assists and 12 digs to lead the Lady 'Toppers over the Lady Pioneers. Attie Forbes and Ella Gay added six and five kills, respectively.
Meghan Carroll had nine digs and seven aces, while Chloe Smith finished with nine assists and Riley Layton ended with six digs.
Crockett was led Brianna O'Shields with five kills and nine digs. Joanna Smith had eight assists and five digs, while Maddie Pleasant totaled five digs and Morgan Barkley coupled four kills with three digs.
"There's volleyball and then there's life," Crockett coach Marquis Clark said. "My team has amazing young people. We didn't play good volleyball this year, so we didn't win many volleyball matches. That's a separate thing from the people they are. They're tremendous kids and my feeling is I wish we could have done more for them to have had success here. It was just one of those seasons. But as far as how hard they train, they work and try as hard as anyone."
Tennessee High 3, Volunteer 1
Kloey Tester finished with 18 kills, 18 digs and three blocks to lead the Lady Vikings to a 25-20, 19-25, 25-19, 25-13 win over the Lady Falcons.
Maggie Hicks finished with 14 kills and Macy Hurley had 23 digs. Sahra Lambert ended with eight kills, seven blocks and 10 digs, while Aubrey McCrary had five 21 assists, 20 digs, five kills and four blocks. Riley McCracken tallied 16 assists.
For Volunteer, which was missing four players, Reneah Barton led with 11 kills and 15 digs. Libero Aubrey Cobb had 21 digs, and Gracie Smith had three kills and 10 digs. Emma Grace Bice finished with eight kills and six blocks. Emily Hatley had six blocks.