The Sooners had built a 5-1 lead, but nearly lost it in the eighth.
That's when the Sooners brought in Steven Bruce who hit the first batter he faced. The Lions gifted OU an out with a sacrifice bunt and the next batter, Tyler Hill, singled in a run.
John struck out James Boulware for out number two, but issued a two-out walk to the next batter, Sean Samsa.
The Sooner lefty was able to get out of the jam by forcing Sherman Thomas to hit into an inning-ending fielder's choice.
John sat the Lions down in order in the ninth to clinch the Sooner victory.
The Sooners could only muster seven hits off five different Pine Bluff pitchers.
Evan Mistich went 1-for-4 in the game, but is lone hit was the difference in the game, as he launched a solo home run to left in the fifth.
The Sooners defeated UAPB 9-4 on Tuesday and is now 10-0 all time VS. the Lions. OU heads to the Nike showcase in Oregon this weekend. The Sooners first game is Friday vs Connecticut.