The favorites all rolled to less-than-stressful wins, including the fourth-seeded host, which stormed to a 25-18, 25-21, 25-13 decision over No. 5 Unicoi County.
In the other two matchups, second-seeded Elizabethton swept No. 7 Chuckey-Doak 25-15, 25-15, 25-13 and third-seeded Sullivan Central took care of No. 6 Johnson County by a 25-19, 20-25, 25-14, 25-10 count.
Tuesday night’s semifinals pit Three Rivers Conference regular-season champion Sullivan South against East at 6 o'clock, to be followed by Central-Elizabethton.
The tourney survivor joins South in next week's Region 1-AA tournament.
Behind the dominant net play of left-hander Sydney Byrd, who led all players with nine kills, East (17-14) ran out to a 14-6 advantage in the first set and the Patriots were barely threatened thereafter.
"The first game started out really well and then we kinda hit a lull," said East coach Tracy Graybeal. "But we persevered and maintained.
"The second game I felt like we kinda let them hang around a little bit, but I kept telling them to keep pushing and pushing along. Unicoi is scrappy and too good of a team to let them hang around.
"And then the third set I thought we played pretty well."
In addition to Byrd's fine game, Graybeal received 21 assists from Ashton Adkins, six digs from Mattie Gouge and four blocks from Kenzie Thomas.
"She (Thomas) had a good night tonight, a real good night," Graybeal said.
BUMMIN' BLUE DEVILS
Disappointed Unicoi County coach LeeAnn Lane, who got nine kills from Shelby Miller, tried to say something positive about her club as its season came to an end, but struggled to find the words and declined to comment.
East now faces the top team in the Three Rivers, but Graybeal is not scared.
"I believe in us," the veteran coach said. "I told them that we need to come out and play our ball (tonight), that we don't need to try and do anything fancy.
"When we play our ball, we're just as good as anybody."