Shetrone overmatched Chaps batters, carrying a shutout into the sixth inning when he had a 9-0 lead and allowing only four hits in an eight-inning performance.
He struck out the side twice and finished with 10 strikeouts.
LCU finally got on the board in the sixth with a two-out double from Blandon Hancock and a single from Michael Harkins.
Shetrone (11-1) also won the series opener for Cumberland, beating Auburn-Montgomery, Ala., 7-1 last Friday. With a loss to spare in the double-elimination tournament, the then-unbeaten Bulldogs held him back from pitching Wednesday when he was available on four days' rest.
The Chaps won that game 6-5. Postseason star Nick Pauza threw 158 pitches in a complete game Wednesday, David Wasylak had gone 81/3 innings Tuesday, and Raymond Pelton had had only two days rest since his last start Monday.
The Bulldogs built their 9-0 lead and got their first 12 hits off Cody Thomas and spot starter/middle reliever Jason Aguirre. The top third of the order set the tone. Alvarez went 4-for-5, and centerfielder Courtney Propst and third baseman Dorian Rojas collected three hits apiece.
Alvarez, the Bulldogs' leadoff batter, drove a two-run homer to centerfield for a 3-0 lead in the top of the fourth.
Cumberland, a school of only 1,400 enrollment located in Lebanon, Tenn., blew it open with a four-run fifth. Rojas doubled leading off, and Thomas hit Alberto Cruz with a pitch - one of his five hit batsmen.
Thanks to a Cumberland baserunning blunder and a force play, Thomas was an out away from escaping the jam with no damage. But he walked Derek DePew, and Steve Selph hit a two-run single to centerfield, making the score 5-0 and chasing Thomas.
After another walk, Alvarez tacked on his two-run single to rightfield. Even though Alvarez was thrown out trying for two bases, Thomas (5-3) was charged with seven runs, six earned, in 42/3 innings. Aguirre gave up four hits in an inning before Pelton and Cody Harris pitched mop-up duty.
A single by Rojas and a double by Nolan McCue made it 9-0 in the sixth.