MIAMI -- Brad Hand finally earned his first win in the major leagues.
Then he was optioned back down to Double-A Jacksonville.
Hand lowered his ERA to 2.77 in five starts.
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"That's all he can do is pitch well when he's here and trust me, it's been noticed what he can do for us," catcher John Buck said. "I've been vocal about it."
Hand received the news of his demotion from manager Jack McKeon after the game.
"I feel I belong up here and hope I stay up here one time," Hand said.
With the All-Star break approaching, Hand will be able to stay on a regular pitching schedule with Jacksonville, but McKeon did not confirm Hand would return to the Marlins after the break.
"You don't know," McKeon said. "I can't honestly say yes or no."
Hand had his longest outing and held the Astros without a hit until one out in the fifth when Clint Barmes singled to center.
"I'm very pleased with my performance," said Hand, who struck out four and walked three.
Mike Stanton homered, Logan Morrison drove in two runs, and Emilio Bonifacio had three hits for the Marlins, who have won six of nine.
"We are starting to look and feel like our old selves," Stanton said. "We got in that big funk as we all know, but it takes little by little and games like these to help us get back on track."
The Astros, who tied a season-low with three hits, have lost six of seven. It was the fourth time they have been shut out this season.
"We had a couple of first-pitch outs to lead off innings against a guy who had struggled with his command, but at the same time, you have to say (Hand) was pitching pretty well," Astros manager Brad Mills said.
Stanton's two-run homer -- his 18th -- to deep left-center field came in his first at-bat since his walkoff homer in the 10th inning on Wednesday against Philadelphia. He had been homerless in his previous 20 games.
"Let's not get carried away because he hits a couple home runs," McKeon said. "I'd like to see him mix in a few line drives too, not just go up there and center on hitting home runs. There's a lot of opportunities to win ballgames with singles, doubles, and we love home runs, but they're not necessary."
Morrison stretched the lead to 4-0 in the fifth with a two-run double just beyond a diving Jason Michaels in left.
"Jay Mi gave a great effort on that ball to left field but he wasn't able to come up with it," Mills said.
Omar Infante singled in a run in the sixth to add to the lead.
J.A. Happ (3-11) lost his seventh straight decision as he issued a career-high seven walks in 5 2/3 innings while allowing five runs and five hits. He struck out eight.
"It's been a struggle all year with that but I'm not going to let it break me," Happ said. "I'm going to keep working and do everything I can do. But it's definitely frustrating right now."
Marlins CF Mike Cameron started his first game since being acquired from Boston earlier this week. Cameron went 0 for 3 with three strikeouts. ... Bonifacio stole his seventh base in his last nine games. ... Happ's seven straight losses is the longest streak of his career. ... Astros RF Hunter Pence went 0 for 3 snapping an 11-game hitting streak.