Clay is returning to the state championship for the first time since they won the Class B title in 1967.
The Blue Devils held off St. Petersburg Lakewood 40-38. The combination of QB Wes Weeks, running back Bilal Ally and receiver J.T. Turner was too much for the Spartans.
Clay plays American Heritage at 1 p.m. Friday at the Citrus Bowl in Orlando for the Class 5A Championship.
Bartram Trail lost a hard-fought battle to Seffner Armwood 35-28 in triple overtime in the Class 6A semifinals.
Armwood started fast and had Bartram Trail down 14-0 in the first quarter, but the Bears defense held the rest of regulation, with an 80-yard drive in five plays to start the second half and a 79-yard drive capped by the first of QB's P.J. Blazejowski's two touchdown passes.
Bartram Trail and Armwood traded scores in overtime, but three incompletions in a row in the losing minutes of the third overtime ended the Bears' season in heartbreak.
Bartram Trail had won eight consecutive games since an 0-5 start, finishing a very successful season 8-6.
In the Georgia A playoffs, a last-second field goal led Charlton County to a 34-33 victory over Irwin County.
The Indians had 289 yards in offense, led by sophomore running back Andrew Lee, who had 24 caries for 228 yards and scored four touchdowns.
Charlton advances to the title game next at 11:30 a.m. Dec. 14 against Marion County in the Georgia Dome. The Indians have won four previous championship games -- three in a row from 2004 to 2006.
Trinity Christian and Bolles Schools each play for a Florida championship on Saturday.
Trinity Christian will take on Clearwater Central Catholic in the Class 3A state championship game at 1 p.m. at the Citrus Bowl in Orlando. Trinity has defeated Father Lopez, Trinity Catholic and Tampa Catholic to earn their spot in the title game.
At 7 p.m., Bolles will face Booker T. Washington (Miami) for the Class 4A state championship. Bolles, a perennial power, has overrun Keystone Heights, Raines and Florida High in their bracket.
This is the third year in a row the Bulldogs have faced Washington in the title game. Each team has one win in the series, but Washington has grown into a powerhouse and is ranked the No. 1 high school team in the nation by MaxPreps and USA Today.