After an exchange of possessions just inside Sam Houston's end of the field, Jen Babcock won the ball and crossed it Cooper whose into the left side of the goal mouth from 14 yards out beat Bearkat goalkeeper Michelle McCollough.
Both teams had other opportunities to win. Cooper had a 15-yard shot one-on-one with the goalkeeper from the right wing that was saved by McCollough late in regulation.
Three minutes into the first overtime, Gayle Ziegler's header on a cornerkick to the near post was saved off the line by a Lion defenders.
With five minutes remaining in the first period of extra time, Kirby Zak had a right-footed shot from the top of the box just skim over the cross bar.
For the complete 107-minute contest, Sam Houston totaled 20 shots and Southeastern Louisiana 14. McCullough was credited with five saves and Lion goalkeeper Cassie Northrup had nine as she picked up the shutout.
The loss drops Sam Houston to 8-10-1 for the year and 4-4 in Southland Conference play. Southeastern Louisiana moves to 10-5-1 for the season and 4-3 in league action.
The match completed Sam Houston's home schedule. The Bearkats will wrap up the 2011 regular season with a match at league-leader Stephen F. Austin next Friday night.