HOUSTON -- A 36-pitch second-inning went a long way to undo Astros rookie starter Hunter Brown on Friday night, though it wasn’t as if the Padres were pounding the ball all over Minute Maid Park. Still, a pair of soft two-out hits with runners on base did some damage nonetheless.

Trent Grishman’s RBI single that was barely out of the reach of Houston Gold Glove shortstop Jeremy Peña broke a tie, and Ha-Seong Kim followed with a soft roller through the right side of the infield to drive in a pair of runs and send San Diego on its way to an 11-2 rout in the series opener.

Brown, who gave up six runs on six hits and two walks to go with five strikeouts in 4 1/3 innings, is 1-3 with a 9.56 ERA and 2.06 WHIP in four starts since he was briefly moved to the bullpen.

“If I’m rolling out there for starts, guys are counting on me and I’ve got to do a better job,” Brown said.

• Games remaining: vs. SD (2), vs. OAK (3), at KC (3), vs. BAL (3), vs. KC (3), at SEA (3), at AZ (3).
• Standings update: The Astros (80-62) are in first place in the American League West by one-half game over the Mariners (79-62), who hold the tiebreaker vs. Houston. The Astros currently are the second-best division winner in the AL, meaning they would bypass the Wild Card Series round.

After scoring 39 runs, including 16 home runs, in three dominating road games against the Rangers earlier this week, the Astros were held to six hits as their home struggles continued. Houston has lost 10 of its past 12 games at Minute Maid Park, including six in a row.

Padres starter Blake Snell, who leads the Majors in ERA, opponents’ batting average, opponent’s OPS and fewest hits per nine innings, held the Astros’ offense to two runs and five hits in six innings to go with eight strikeouts.

“He was throwing 96, 97 [mph] with his fastball and then he would get two strikes, and he was throwing hard enough where you had to commit on that breaking ball,” manager Dusty Baker said. “He’s good. We just couldn’t get anything going other than that one inning."

Brown needed only 11 pitches to complete a 1-2-3 first inning before throwing more than three times that many in the second, when the Padres scored four runs. The two-out RBI single by Trent Grisham, who got jammed by a fastball, left the bat at 61.5 mph, according to Statcast, and was nearly snagged by Peña. Kim’s two-run dribbler had an exit velocity of 79.5 mph.

“Obviously, it’s really frustrating,” Brown said. “I thought I made some good pitches there. … To Grisham, I thought I made a pretty good pitch. It was probably two inches away from falling in Peña’s glove. I think all that kind of stuff compounded and they were able to put four runs up.

“Honestly, yeah, it’s really frustrating, especially scoring a run early on [Snell], who’s obviously a really good pitcher. So yeah, that was tough.”

José Urquidy, a starter-turned long reliever, threw the final four innings and didn’t fare much better, giving up five runs on four hits and two walks. Urquidy has a 6.75 ERA in four relief outings this season.

“Both of them are struggling a little bit right now,” Baker said.

Brown did give up some hard-hit contact. He was tagged for a third-inning homer by Xander Bogaerts, but it was the soft hits in the second inning that bothered him the most.

“If I make good pitches, usually it goes pretty well,” Brown said. “Tonight, I didn’t in the second inning, in particular. I thought even the home run, a 3-1 fastball to Bogaerts, was up and in. I have to start controlling some of the things I can control -- falling behind guys, walking leadoff guys, guys at the end of the order. Those are the things I can handle.

“I can’t control a ball that's hit 68 or whatever mph and falls, and keeps an inning going. Obviously, it hasn't been going well lately and I have to put my head down, and try and right the ship, really.”

Baker was hoping a switch in catchers would help get Brown on track. Veteran Martín Maldonado caught Brown for the first time since July 7 after rookie Yainer Diaz had caught Brown for much of the season.

Maldonado said he felt Brown was rushing a bit with runners on base, trying to be quicker to the plate against a Padres team that stole five bases.

“I felt like he lost the strike zone,” Maldonado said. “There were a couple of lucky hits they got, especially in the second inning. I felt like the whole game, we couldn't put guys away after we got ahead, 0-2, 1-2.”