Martin Maldonado spoiled right-hander Anthony Bass' outing.
Maldonado hit a grand slam and the Milwaukee Brewers used 10 newcomers in beating the San Diego Padres 4-3 on Tuesday night.
"One swing of the bat," Padres manager Black said. "I was telling Anthony that most times when a starting pitcher takes the mound, they're going to be stressed at least one time."
That moment came in the third inning when Bass (2-8) had two outs, a runner at first and Ryan Braun at the plate.
The right-hander walked both Braun and Travis Ishikawa, and Maldonado hit a 2-2 pitch into the left-field bleachers for his first grand slam and eighth home run of the year.
"There's usually a moment in the game when it's critical and you have to step back and realize this is that moment," Black said. "I think the Ishikawa at-bat was that moment and after he walked him, the Maldonado at-bat became that moment."
The Padres started Bass, who has been pitching in relief since returning from a shoulder injury in early September. He was limited to 60 pitches, and allowed only one hit and one walk in the first two innings, but ran into trouble as his pitch count climbed in the third.
"Physically, I felt fine," Bass said. "It's one of those things where you have to execute a pitch in those situations and I didn't."
Jim Henderson (1-2) pitched a perfect seventh inning for his first major league win. John Axford worked the ninth for his 35th save in 44 chances, throwing a slider to Logan Forsythe for a ground out with a runner on the third to end it.
"It came down to some good pitches at the end for both sides," Black said.
The Brewers started right-hander Tyler Thornburg and fellow rookies Norichika Aoki, Logan Schafer, Maldonado, Taylor Green, Jean Segura, Jeff Bianchi and Maldonado. Rookie Eric Farris pinch-hit and rookies Brandon Kintzler and Henderson pitched in relief.
Will Venable's RBI single scored Chase Headley in the fourth to pull San Diego within 4-1.
The Padres scored twice off reliever Manny Parra in the sixth to make it 4-3. Headley singled, moved to second on Yonder Alonso's walk and scored on pitch-hitter Jesus Guzman's single. Venable was hit by a pitch to load the bases, chasing Parra.
Pinch-hitter Yasmani Grandal's infield single off Kameron Loe scored Guzman to make it 4-3. Loe struck out pinch-hitter Carlos Quentin to leave the bases loaded.
Everth Cabrera had three hits and Headley had two hits for the Padres. Headley was selected as the NL Player of the Month for September. He won the award in August, too.
NOTES: The Brewers scratched RHP Yovani Gallardo for Wednesday's start, opting to rest their ace instead of having him pitch in a meaningless game. Josh Stinson will start instead. ... Headley was selected NL player of the month for September. He won the award in August, too. ... Roenicke said before the game that the entire coaching staff would return in 2013. ... Roenicke said most of the starting position players likely would play in the season finale Wednesday.