O'Brien allowed a hit and a walk while striking out one over a scoreless inning to pick up the save Friday against the Diamondbacks.
The 31-year-old produced an eighth straight scoreless appearance and is once again tied with Mason Miller atop the National League with 25 saves. During that scoreless stretch, O'Brien has surrendered just three hits and three walks while recording seven saves, though he hasn't been particularly dominant with seven strikeouts.