The Pirates beat the D-backs 3-2 in 10 innings on July 27, turning a chase-pack matchup into a real playoff-race swing.
Arizona led 2-0 in the sixth after Max Kepler doubled home Corbin Carroll and Geraldo Perdomo, but Pittsburgh stayed close.
Brandon Lowe drove in the Pirates' first run later in the inning, tied the game with an RBI double in the eighth, then delivered the walk-off single in the 10th.
Lowe finished 3-for-5 with a double and two RBI.
What It Means
The Pirates improved to 55-52, while the D-backs fell to 55-52.
BaseChaser lists Pittsburgh at 38.2% to make the playoffs. Arizona sits at 38.4% after dropping three straight.
These two teams are now separated by almost nothing on the board. For Pittsburgh, it was a direct climb into Arizona's lane. For the D-backs, it was another lost chance to protect cushion.
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