HOUSTON -- The best cure for a struggling bullpen is a dominant starting pitcher.

Astros veteran right-hander Zack Greinke stepped up to play the role of stopper Sunday afternoon, holding the Padres to one run -- on a solo homer to Webster Rivas in the fifth inning -- in eight innings in a 7-4 win in the series finale at Minute Maid Park.

Greinke’s stellar outing came on the heels of back-to-back extra-inning losses to the Padres, who rocked the Astros bullpen for 19 runs (11 earned) in 13 2/3 innings in the first two games of the series. Greinke allowed six hits -- five singles in addition to the homer -- walked one batter and kept the bullpen usage to a minimum.

“I knew I was going to have to throw all 100 pitches, whether that was five innings or seven innings,” Greinke said. “I was just kind of planning on trying to just do what I could.”  

The Astros tagged Padres starter Blake Snell for seven runs in three innings, including a three-run homer by Kyle Tucker to cap a four-run first and a two-run double by Aledmys Díaz in a three-run third inning. The runs were much-needed, considering Astros reliever Andre Scrubb gave up a pair of home runs in the ninth inning.

“In every ballgame, no matter what the score is, taking the last breath out of them is tough,” Astros manager Dusty Baker said. “They always mount a rally in the eighth or ninth inning, and it’s always started by a blooper or a walk and then next thing, you’re in trouble. We were trying to think positive. Lightning struck twice the last two days. I had to change the saying -- lightning can't strike three times in the same place. I was trying to think positive and, ‘C’mon Scrubb.’” 

Greinke (5-2) has a 2.79 ERA in his last four starts and now ranks second in the American League with 73 2/3 innings pitched. The Astros are 9-3 in games he starts and 19-21 in starts by everyone else.

“This guy earns his money,” Baker said. “He works hard and pays attention, and he enjoys pitching. He’s a consummate team guy. He knows what the team needs. He knew we needed him to keep us in the game. That was his mindset all the time, especially when you know your team’s in trouble. That’s what aces do.”

Greinke threw 104 pitches -- three off his season high -- and relied mostly on his fastball (47 percent) and changeup (28 percent) mix. His velocity topped out at 89.3 mph. He gave up six balls that were hit at 100 mph off the bat or more, three of which went for hits, including the homer. Two of those were long fly balls to center off the bat of Tommy Pham (389 feet) to start the game and Wil Myers (367) in the sixth.

“My stuff was pretty good,” he said. “My command wasn’t, like, perfect with everything, but it was moving pretty good, and the location was solid. They were close on a decent amount of balls. They hit some far ones, but they went to center field. I was lucky it was to center field.”

Despite the struggles of his bullpen -- which posted an 8.59 ERA in the three-game series -- Baker wasn’t about to let Greinke try to throw a complete game. A seven-run lead was good enough, though the Padres did move the potential tying run to the on-deck circle, following homers by Myers and Ha-Seong Kim off Scrubb.

“Greinke was outstanding,” Baker said. “He had everything going for him. We made some good defensive plays. We turned some double plays at the right moments, which helped him get into the eighth inning. We badly needed this to give our bullpen a rest, because we didn’t have four guys [available, including Ryan Pressly, Ryan Stanek and Brooks Raley].”