HOUSTON — So much needed to go right for Sam Gaviglio and the Mariners to come out victorious against the Houston Astros on Tuesday night and extend their winning streak to six games.

With a fatigued bullpen short on available arms, the Mariners needed to score a bunch of runs off Astros starter Brad Peacock, something that hasn’t happened much this season. Gaviglio needed to work on the edges of the strike zone and have an umpire willing to call them strikes and limit damage against a potent Astros team while also giving his team at least six innings of work.

Few of those things really happened, and as a result the Mariners’ string of consecutive wins came to a halt with a 6-2 loss to the Astros at Minute Maid Park.

Seattle slipped back under .500 to 47-48. The series and trip closes out on Wednesday afternoon with left-hander James Paxton getting the start.

“Coming in here, the goal was to win the series, and we still have a chance to do that tomorrow with Paxton on the mound,” manager Scott Servais said. “So we feel good about that.”

So about those needs for victory on Tuesday?

Well, the Mariners didn’t score a bunch of runs against Peacock. Using an effective slider and taking advantage of plate umpire Dan Bellino’s low strike zone, Peacock pitched seven innings, allowing just one run on three hits with a walk and nine strikeouts.

“Peacock threw a good ballgame tonight,” Servais said. “He was right on the edges with his stuff tonight and he has been throwing the ball well, too. But we had been swinging the bats so well that you kind of expect us to go out and put up some big numbers tonight. But we just didn’t have much going offensively.”

Peacock improved to 8-1 and lowered his ERA to 2.40 while pushing his strikeout total to 93. The seven complete innings surpassed a personal barrier for him. It was the first time since Sept. 5, 2013, that Peacock had pitched seven complete innings in a start — a span of 42 starts.

“He was throwing that slider for strikes and getting ahead with that,” Kyle Seager said. “And his fastball had a lot of life on it. It really jumps out of his hand. He was attacking and aggressive.”

The Mariners’ lone run against him came in the fifth inning after Seager led off with the 200th double of his career — a line drive to deep left-center. He scored from third on Jarrod Dy­son’s infield single. That run cut the lead to 5-1.

“I didn’t even know about that,” Seager said of the 200 doubles. “That’s obviously pretty good. Hopefully I will keep adding on to that.”

As for Gaviglio, his command was decent at times. He tried to pitch to the edges of the strike zone, but Bellino didn’t seem interested in rewarding him with strike calls. The issues with Bellino’s calls or lack thereof led to pitching coach Mel Stottlemyre Jr.’s ejection between the second and third innings for arguing balls and strikes.

“We felt the strike zone was a little too liberal at the bottom of the zone,” Servais said. “Guys were emotional and getting fired up and the umpire didn’t like it.”

Forced to work more in the strike zone, which isn’t a good thing for a right-hander without plus velocity or breaking stuff, Gaviglio fell behind in counts and got knocked around by a Houston lineup that was missing All-Star shortstop Carlos Correa, who went on the disabled list on Tuesday with a torn ligament in his thumb. Correa injured the thumb on a swing and a miss on Monday night and will undergo surgery. His expected two-month absence wasn’t felt much in his first game away.

Gaviglio pitched six innings, giving up five runs on eight hits with two walks and two strikeouts. He gave up a pair of solo homers to the Astros lumberjack of a catcher, Evan Gattis.

“I didn’t get into a rhythm early and I was always working from behind and they took advantage of that,” Gaviglio said.

The Astros could have done more damage if not for their own baserunning gaffes, which included having two runners thrown out at third base to end innings. The first of those miscues cost Houston a run in the third. With runners on second and third and one out, Yuli Gurriel hit a fly ball that appeared to score Jose Altuve from third on a sacrifice fly. The Mariners threw to third to try to get Josh Reddick, who was tagging up from second. Initially, third-base umpire Adam Hamari called Reddick safe.

The Mariners challenged the call and replays showed Reddick losing contact with the bag with Seager tagging him. The replay also showed that Reddick was tagged out before Altuve had crossed home plate. The run was taken away as the double play ended the inning.

Emilio Pagan, one of the few relievers that hadn’t been taxed too much, gave up a run in the seventh, but mopped up the remaining two innings to provide some rest for his fellow relievers.

Down 6-1, Seattle scratched out a run in the eighth against the Astros bullpen on an RBI single from Ben Gamel that scored Carlos Ruiz. Seattle threatened for more, putting two more runners on base with two outs. Nelson Cruz, who had homered in his previous three games, stepped to the plate with a chance to cut the lead to one run. Instead, Luke Gregerson struck him out to end the inning.

Wild things

AL wild-card standings:

Team

W-L

GB

Tampa Bay

49-44

+1

N.Y. Yankees

47-44

—

Minnesota

47-45

0.5

Seattle

46-47

2.0

Kansas City

45-46

2.0

Texas

45-47

2.5

Ryan Divish: 206-464-2373 or rdivish@seattletimes.com