The junior from Southlake drove in five RBIs to lead MSU to an 8-4 win in the season finale after Texas A&M-Kingsville claimed the first game of the day by a 9-4 margin.
Midwestern closes the campaign with an even 24-24 record. The Mustangs have not experienced a losing season in the 12 seasons since bringing back softball in 2004.
The Mustangs finish seventh in the Lone Star Conference standings at 11-17 and will miss the league's postseason tournament for the first time.
Vinson mashes two homers as Mustangs salvage split at TAMUK, avert losing season
Senior third baseman Kelley Schaefer closed out her career on a high extending her season-ending hitting streak to 10 games. The Waco native hit .485 (16-for-33) during the run with six homers and 17 RBIs.
Schaefer closes her career as the program's all-time RBI leader with 199 and is third on the all-time homers list with 41.
Schaefer drove in the Mustangs' first run of the second game on a single to left field to plate junior outfielder Haley Howerton, who had reached the first of two infield singles in the game.
Howerton scored two more runs as Vinson drilled a three-run homer to left field in the second inning then blasted a two-run shot in the sixth.
Vinson finished the season hitting .327 and led the team with 18 homers and 49 RBIs. She heads into her senior season just four homers shy of Kim Jerrick's record of 56 home runs.
Schaefer drove in three of Midwestern's four runs in the opner as the Mustangs led 4-2 heading into the bottom of the fifth, but Texas A&M-Kingsville exploded for seven runs in the frame to take control of the game.
Howerton notched her 10th and 11th multiple hit game over her last 14 outings with two hits each game to up her season batting average to a team leading .371.
Texas A&M-Kingsville finished the season with a 17-27-1 mark while closing eighth in the LSC at 8-19-1
Midwestern State earned its sixth straight appearance in the South Central/West Regional Saturday when the NCAA Division II Men's Golf Championship Committee released the 2015 postseason field.