HOUSTON -- It was clear on Thursday night that the Orioles and Astros are headed in opposite directions.
Except it's not last-place Houston that's backsliding. Baltimore -- which has yet to fire on all cylinders -- continued a frustrating stretch, as its previously high-powered offense went missing and the oft-used bullpen gave way to a two-run homer to red-hot rookie George Springer.
The result, a 3-1 series-opening loss at Minute Maid Park, puts the Astros at 12-6 since winning the series finale in Baltimore earlier this month. The Orioles? 6-12.
With the defeat, the O's (26-26) dropped to .500 for the first time since April 27, squandering a quality start from Ubaldo Jimenez (six innings, eight K's) in the process.
"It's not always going to click together," manager Buck Showalter said of his team's recent inconsistencies. "You're hoping one part of the game is good enough to offset the others, and we have for the most part. I have a lot of confidence that our best baseball is ahead of us. Tonight we just didn't swing the bats well enough. Ubaldo deserved a better fate."
Jimenez left the game with the score tied at 1, and reliever Preston Guilmet -- who had thrown six scoreless innings going in -- allowed his first hit of the season, Jose Altuve's one-out seventh-inning single. Springer made him pay, sending a full-count pitch into the stands for his seventh homer in as many games.
"I just left a pitch up in the zone," Guilmet said of his first earned runs, and loss, of the season. "That was the one that got hit. A couple of other pitches were up, too. In general, [I was] a little up in the zone tonight."
Springer's 10 homers in May extended an Astros rookie record and gave Houston a lead it would never relinquish.
"He's an exciting player," Astros manager Bo Porter said. "At any moment he can change the game with one swing. It doesn't matter of he's 0-for-4 or 3-for-3, he has the ability to impact the game every time he steps into the batter's box."
Guilmet, in his third stint with Baltimore's revolving roster, has been increasingly given more responsibility as Showalter tries to spread the relief corps' heavy workload and navigate through the later innings.
"Just one [pitch], the pitch he left out over the plate, didn't quite have the bite it has [normally]," Showalter said of Guilmet's fateful offering. "I like to see how guys respond. I know he's down there, but he comes right back and gets some outs and gets us back in the dugout. We had a shot. We just didn't mount a whole lot. We had one semi-opportunity there and couldn't do anything with it."
Jimenez kept the Astros from cashing in on their opportunities, with Springer's blast their first hit in 13 at-bats with runners in scoring position as the righty navigated out of trouble all night. Signed to a four-year, $50 million deal this winter, Jimenez gave the Orioles just their 18th quality start in 52 games and third in their last 11.
"In a perfect world, you don't want to get so many runners on base like I did, because anything can happen," said Jimenez, who allowed three hits and three walks in the eight-strikeout performance. "A blooper, a base hit, and they're going to score. But it's part of the game. Once they get on base, you have to find a way to get them out."
The lone run Jimenez did allow came on a close play in the second inning that stood as called after a review.
After Jimenez loaded the bases on a pair of walks and a single, his first pitch to Robbie Grossman skipped off catcher Nick Hundley, who fired the ball to a hustling Jimenez covering the plate. The throw beat Jason Castro, but Jimenez's tag was close, and Castro was ruled safe.
"I'm pretty sure I had him, because his cleat got caught on my glove," said the typically reserved Jimenez, who tumbled over afterward and was animated after the call by home-plate umpire Mike Muchlinski. "He almost made a hole in the glove. That's what I was trying to show the umpire. He never touched home plate. I have the hole mark from his cleat on my glove."
Showalter came out to argue and, after a review that lasted four minutes and 25 seconds, the run stayed on the board, the call standing in official terms.
"I don't know how you get much more conclusive than what we saw," Showalter said. "But I don't know what they're looking at. They're supposed to have the same look we have. [The play] didn't beat us."
But Brad Peacock did. The Astros' starter, who was scratched from his last scheduled start with soreness in his forearm, needed just 53 pitches over four innings and struck out eight with no walks over a solid six frames.
"He was definitely pounding the zone tonight, no question about it," said first baseman Chris Davis, who went 0-for-4. "I thought we had decent at-bats against him. I don't think we swung at a lot of balls out of the strike zone. But at the same time, when a guy's got four pitches working, you've got to be ready for anything."
Thursday's game marked just the second time this season that Peacock issued fewer than two walks, and the first time in his career he issued none.
The Orioles got a game-opening single from Nick Markakis but didn't have another baserunner until Steve Pearce hit a one-out double in the fourth. The red-hot Pearce, who was moved up to second in the batting order, scored on Nelson Cruz's single into right to tie the score at 1.
Cruz, who homered twice in Wednesday's loss and has a Major League-leading 19 long balls, extended his team lead in RBIs to 49. But that was all the O's would get, as Astros reliever Josh Fields held them to one hit over the next two frames before closer Chad Qualls picked up his fourth save.
"I think if there was an easy fix, we would have found it by now," Davis said of getting the club back on track. "It's kind of the nature of the beast. Sometimes you are playing well and you are not clicking on all cylinders but able to get away with it. Right now we are obviously not able to get away with it. I thought Ubaldo pitched really well tonight. Then again, so did their guy."
Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Facebook and Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.