The victory sent the Millers to 11-0 on the season and 8-0 in league play.
The Millers struck first in the top of the first inning courtesy of a walk, an error and one hit.
Ryan Leonards walked to start the contest and then scored from first on an error by the Seminoles’ third baseman. Bryant Gilbert, who reached base on a fielder’s choice, then scored on a single to center by Matt Savoie.
Opelousas answered back in the bottom of the inning when Scott LaGrange singled and scored on an errant throw by Crowley catcher Blaine Richard. Myles Taylor, who reached base on the error and advanced all the way to third, scored on a single by Darrin Handy.
The Millers took the lead again in the top of the second when Mitch Corzine drew a walk and scored on another Opelousas error. Jake Trahan, who reached on the error, later scored on a single to right field by Beau Desselle to put the Millers in front, 4-2.
Opelousas tied the game at 4-4 in the fourth inning and threatened to take the lead but a heads up play by Trahan on a squeeze bunt nailed the potential go-ahead run at the plate to end the threat.
The Millers took the lead for good in the top of the fifth, scoring six runs on five hits - three for extra bases - off Seminole starter Darrin Handy and relievers Logan Stelly and Nick Escoyne. Savoie logged an RBI triple in the inning while Justin Desselle and Austin Robichaux each drove in single runs with doubles.
Crowley added an insurance run in the seventh when Frem Reggie singled and scored on a single to right field by Tyler Dupuis.
Trahan, who started the game on the mound for the Millers, made the lead stand over the final three innings. He sat the Seminoles down in order in each of the final three frames, surrendering just one hit in the seventh before ending the game on a double-play ball.
Trahan pitched all seven innings, giving up four runs (two earned) on six hits and one walk. He struck out six.
Savoie, Justin Desselle and Robichaux paced the Millers with two hits each while Trahan, Corzine, Dupuis, Beau Desselle, Richard and Reggie each had one hit.
The Millers return to league action Tuesday when they play host to Eunice at 7 o’clock.