After losing the first set, The Lady Trojans split the next two before wrapping up a 27-29, 25-16, 19-25, 25-10, 18-16 victory.
Kell (16-21) had match point in the fifth set leading 14-11, but Caylee Yanes totaled three of her five aces to serve Lassiter back even before it went on to earn the fifth-set victory.
Sam Link had 37 assists and 17 digs for Lassiter, while Libby Bochniak collected 20 kills and 17 digs. Yanes also had 15 digs.
Lassiter will host Area 4AAAAAA rivals Woodstock and Cherokee on Tuesday for senior night.
Hillgrove 3, Sprayberry 1: After losing the first set, the Lady Hawks came back to win the next three and beat their county rival 22-25, 25-18, 25-14, 25-19.
Chioma Okonkwo led Hillgrove (18-17) with 18 kills, to go along with five digs and three aces. Mackenzie Engram added eight kills, four blocks and an ace, while Janna Jernigan had eight kills, seven aces and five digs.
Allison Purdue also had an effective service game, with seven aces, while Myah Martin had 38 assists.
Hillgrove will travel to Creekview on Tuesday for a non-area tri-match with Allatoona.
Allatoona splits: Jaslynn Gwyn had 14 kills and six blocks to lead the Lady Buccaneers in a non-area tri-match.
Allatoona defeated Cartersville in three sets (23-25, 25-7, 25-13), but it fell to Kennesaw Mountain (25-23, 25-19).
Jenna Usry had 16 kills, Katie Cory finished with 28 digs and Deborah Adeyeye added 19. Julia Douglas also had nine aces.
The Lady Buccaneers (20-15) will travel to Creekview on Tuesday for a tri-match that also includes Hillgrove.
South Cobb 8, Westlake 4: The Lady Eagles rallied from a 2-0 first-inning deficit to post a non-region home win in their regular-season finale.
South Cobb (21-7) scored four runs in the bottom of the first for a 4-2 lead, and scored four more in the fourth for the 8-4 margin.
Becky Collins was 2-for-4 with an RBI and a run scored for the Lady Eagles, who took advantage of eight walks and stole six bases. Terilyn Harris batted 2-for-4 with two RBIs, while Tyonna Williams had an RBI and Emily Cargle scored twice.
Brittney Rhodes (19-5) gave up four runs on six hits while striking out four in the complete-game victory.
South Cobb will face Campbell in a Region 4AAAAAA tournament game Monday at North Cobb.
North Cobb 7, Kell 1: The Lady Warriors sent 10 batters to the plate in the bottom of the third inning, totaled five hits and scored six runs to help with the non-region home victory.
Casey Page batted 3-for-4 with an RBI and two stolen bases to pace North Cobb (20-8), which had 11 hits. Jordan Lewis was 2-for-4 with an RBI and a stolen base, while Taylor Krause batted 2-for-3 with two doubles and two RBIs.
Sarah Merced was 2-for-3 with an RBI and Kayla Trumbull batted 1-for-2 with an RBI. Bryanna Vazquez also had an RBI.
Olivia Mould (14-4) collected the win after giving up one unearned run on three hits while striking out two in six innings.
Jill Torres had an RBI for Kell.
North Cobb will host either South Cobb or Campbell on Monday in the Region 4AAAAAA tournament.
Sprayberry 1, Mount Pisgah Christian 0 (8 inn.): Katie Reed scored the winning run with two outs in the bottom of the eighth to lift the Lady Yellow Jackets to a non-region victory.
Reed scored on an error.
Charlie Smith went the distance, pitching a one-hit shutout while striking out five.
Sprayberry (11-15) will host McEachern today.