The Pirates plated the go-ahead run in the seventh when third baseman Christian Villanueva booted a routine grounder with two outs. Three innings prior, they scored three times -- all coming after Franchy Cordero got a dreadful break on a fly ball to left.
"Today was one of those rare days for us that we didn't make plays," said Padres manager Andy Green.
Entering Thursday, the San Diego defense ranked third in the Majors with 25 defensive runs saved. They've upgraded at shortstop with Freddy Galvis, at first with Eric Hosmer and in right with Travis Jankowski.
Thursday night told the other half of that story: Villanueva has been shaky, and Cordero has struggled with his reads and his routes. In the fourth inning, Cordero froze on a ball hit well in front of him. By the time he reacted, it was too late, despite the 99-percent catch probability, according to Statcast™.
Cordero's poor route to the baseball doubled the damage. It kicked away and turned one base into two for Pirates left fielder Corey Dickerson.
Given Cordero's speed and athleticism, the Padres feel he could be an above-average defender one day. But he came through the system as a shortstop and is only three years into his tenure as an outfielder. There's work to be done before he reaches his potential.
"The more he plays out there, the better he's going to be," said outfield coach Skip Schumaker. "That's just the reality of it. Outfield is the toughest place to get live reads. He works hard, it's just going to take time, but he'll be fine."
Padres left-hander Eric Lauer allowed four runs over 4 2/3 innings, walking three and allowing six hits. His line wasn't great, but he was worlds better than his previous start in which he allowed six Cardinals runs and couldn't make it through the third.
Lauer was done in by some tough luck on batted balls. His command greatly improved, and his fastball velocity jumped back into the low-90s after sitting in the upper-80s last start.
The command part of the equation meant more to Lauer.
"I don't know why it was down," Lauer said of his velocity. "I don't think my velo is a huge factor, because I don't throw 97 [mph]. As long as I'm making pitches, I don't care if it's 86 or 92."
Through three innings, Lauer had allowed one baserunner.
"It should be a revelation for him: 'Oh that's how I pitch here -- aggressively,'" Green said of Lauer's first trip through the order.
Lauer's command escaped him in the fourth, but it was a relatively encouraging bounce-back effort for the 22-year-old rookie. He's in the Majors well ahead of schedule, and he held his own Thursday night in Pittsburgh.
The Padres' defense did not.
MOMENTS THAT MATTERED Lauer power: Before his big league callup last month, Lauer hadn't recorded a hit at any level since high school. He sparked a fifth-inning rally with a double on Thursday night -- his second hit in seven at-bats this season.
Stranded in the sixth: The Padres put two men in scoring position in a tie game in the sixth inning, but they couldn't capitalize. With Raffy Lopez running on contact from third, Manuel Margot hit a sharp grounder to third baseman David Freese, who threw home in plenty of time to nab the potential run from scoring. Pinch-hitter Matt Szczur popped out to short to end the threat.
YOU GOTTA SEE THIS With seven hits in his past four games, Galvis appears to have broken out of his slump. But he took exception to a strike three call from home-plate umpire Will Little in the top of the eighth inning and was ejected for arguing and throwing his helmet.
That put the Padres in a bit of a bind. They don't carry a traditional backup shortstop. Villanueva, their No. 2 option, was at third, having already pinch-hit for Cory Spangenberg, the club's other third-base option.
Enter Carlos Asuaje. He began taking grounders at third base earlier this week, and the Padres had hoped to slowly transition him back to the position he played with Boston before he was traded. There was nothing slow about this transition. Asuaje entered in the eighth and made a lunging play to snare a Jordy Mercer liner. Then, he made a nice stop on a Jose Osuna grounder.
"It was nice to knock a little bit of the rust off," Asuaje said. " ... I think I've been a pretty consistent defender [at second] for a couple years now, and a lot of those things just translate in the infield."
UP NEXT Tyson Ross has been the anchor of the Padres' rotation this season, and he'll take the ball Friday against Ivan Nova and the Pirates. First pitch is slated for 4:05 p.m. PT at PNC Park. Ross, who owns a 3.40 ERA this season, should surpass the 50 innings mark on Friday. He didn't hit 50 for Texas all last season, after coming off major shoulder issues in 2016.