O'Brien picked up his fourth save Friday against the Red Sox, striking out one in a hitless and scoreless ninth inning.
O'Brien entered in the ninth with a 3-2 lead and set the Red Sox down in order on eight pitches, six of which he threw for strikes. After Ryne Stanek opened the season as St. Louis' closer, O'Brien has recorded four straight saves for the Cardinals. He's yet to allow a run and owns a perfect 8:0 K:BB across 8.1 innings.