HOUSTON -- Seattle starter Hisashi Iwakuma shut down the Houston Astros for seven innings on Sunday.
Then the Mariners went to the bullpen and things went downhill quickly.
Rookie Brett Oberholtzer pitched a four-hitter and Jason Castro hit an RBI double in the eighth inning, lifting the Astros to a 2-0 win over the Mariners.
The 24-year-old Oberholtzer (4-1) struck out five and walked one. He did not allow an extra-base hit in his sixth career start and ninth appearance to lower his ERA to 2.79. He had never pitched more than seven innings entering Sunday's game.
Iwakuma scattered six hits and struck out seven. It was the third time in four starts that he'd pitched seven innings. He didn't argue when manager Eric Wedge took him out with 99 pitches.
"I'm just out there to do my job," he said through a translator. "If the skipper wants me to go another inning, I will go. If not, I'm totally fine with that.”
Charlie Furbush (2-5) took over for Iwakuma in the eighth and Jose Altuve greeted him with a double that rolled into the corner of right field. Castro followed with a ground-rule double that bounced into the bullpen in right-center to give Houston the lead.
"He was up on the pitch to Castro it looked like," Wedge said of Furbush. "The first hit you tip your cap to him. He sticks his bat out there, he's trying to hit a pitch away and a good hitter went right over the bag. You can't defend against that.”
Castro advanced to third on a fly out before scoring on a bunt single by pinch-hitter Brandon Barnes. Barnes tried to bunt on the previous pitch but it popped foul.
Furbush said he couldn't remember a time when a team tried a squeeze twice in a row.
"You kind of know it's coming," he said. "I just didn't think it was going to happen two times in a row.”
Second baseman Nick Franklin was disappointed that he didn't help make the play on the bunt.
"It's one of those things right when I saw the runner take off, I took off immediately, hoping that he'd push the ball toward me," Franklin said. "I ended up being wrong in that case and I was supposed to cover first. It's just a mistake you learn from. It's the first time that's ever happened to me. It's something to learn from, which is key.”
Kyle Seager singled with one out in the ninth. Right fielder L.J. Hoes sprinted to make a sliding catch in foul territory on a ball hit by Kendrys Morales for out No. 2 before Franklin Gutierrez also hit a fly ball caught by Hoes to end it.
Trevor Crowe, who was recalled from Triple-A after Saturday night's game, added two hits as the Astros avoid a four-game sweep.
Oberholtzer was perfect in the seventh and eighth innings -- with a little help from his defense. Altuve scooped up a hard-hit grounder headed for the outfield and made a leaping throw to beat Dustin Ackley to first base for the first out of the eighth inning.
Oberholtzer retired the first six batters he faced before walking Justin Smoak to start the third. A two-out single by Brad Miller sent Smoak to third, but Oberholtzer struck out Franklin to end the threat.
"He was just keeping us off balance," Franklin said of Oberholtzer. "He mixed up his pitches well and we didn't have any timely hits to go along with it.”
The Mariners managed one-out singles in both the fourth and the sixth innings, but left both players stranded when they couldn't string together any hits. Oberholtzer pitched a 1-2-3 fifth inning in between those frames.
Houston threatened in the second inning. Matt Dominguez led off the bottom of the inning with a single, but was out at second on a force play on a ball hit by Brett Wallace. A single with two outs by Crowe left Wallace at third. But the Astros came away empty-handed when Hoes grounded out.
Chris Carter walked with two outs in the fourth and reached third on a double by Crowe. Another groundout by Hoes ended that threat, too.
Iwakuma yielded a single to Wallace with one out in the sixth inning before retiring the last five batters he faced, with two strikeouts.
NOTES: The Mariners recalled former closer Tom Wilhelmsen Triple-A Tacoma on Sunday to begin what is expected to be a number of September callups. He has 24 saves this season. He got the last out of the eighth inning. ... Sunday was the 10th game of 20 in a row for the Astros. Their next day off is Sept. 12. ... Houston opens a three-game series with Minnesota on Monday when Astros right-hander Paul Clemens opposes Andrew Albers. ... Seattle ace Felix Hernandez is scheduled to pitch on Monday against Kansas City's Danny Duffy in the opener of a four-game series.