Tanner Donnels went 6-for-6 with the game-winning RBI in the bottom of the 13th.
LMU has won four straight games headed into the weekend.
The annual Crimson/Navy Fall World Series will begin Wednesday and continue on Friday and Saturday.
LMU will play a three-game WCC series at Saint Mary's this weekend.
LMU will begin WCC play at Pepperdine this weekend.
Sixth-year head coach Jason Gill previews the 2014 LMU baseball season.
BASE | LMU 5, #26 Oklahoma State 2
2013 Baseball Season Preview with head coach Jason Gill.
Interviews with the player-managers prior to the start of the 2012 Crimson/Navy World Series
The LMU baseball team held its annual Halloween costume practice on Wednesday.