Eric Hosmer provided a 2-run double off the centerfield wall in the top of the fifth inning to give the Friars a 4-3 lead.
But the other Eric (Lauer) and reliever Matt Strahm were let down by some spotty defense and the Pirates were able to capitalize off San Diego’s mistakes to earn a 5-4 victory.
Strahm was trying to pitch out of a jam with the game tied 4-4 in the seventh when Corey Dickerson bounced one to third base.
With Gregor Polanco on third, Padres infielder Christian Villanueva could not field the ball cleanly on the hop and was unable to make a throw over to first.
Polanco scored what would prove to be the game-winning run as a result.
Another base hit that knocked in a run for Pittsburgh earlier in the fourth could have easily been ruled an error.
Padres left fielder Franchy Cordero misread the ball off the bat when Lauer was trying to coerce Dickerson into a fly ball. Cordero did not take a good angle to the ball and it wound up getting behind him.
Pittsburgh rallied to score three runs in the frame and take a 3-2 lead after Hosmer and Jankowski had helped manufacture a couple runs in the top of the third.
La Mesa native Steven Brault pitched 2.1 shutout innings of relief for the Pirates and struck out three.
The Grossmont high school alum even smacked a double in the bottom of the sixth inning and is batting a solid .273 this season at the plate (3-for-11).
Pittsburgh’s relievers were stellar down the stretch as well.
Michael Feliz struck out Freddy Galvis looking to end the eighth on a borderline pitch that was thrown high.
Galvis took exception and was ejected shortly after slamming his helmet to the ground.
Felipe Vazquez proceeded to strike out the side during a scoreless ninth.
Former 2006 Padres draft pick David Freese added a single and a sacrifice fly.
San Diego will try to regroup Friday when Tyson Ross takes the hill. Pittsburgh plans to counter with Ivan Nova.