The beneficiary was Astros starter Lucas Harrell (2-2), who helped the Astros win twice in the three-game series before heading on a seven-game road stretch in Boston and New York.
"That felt like a complete game," Astros manager Bo Porter said. "We pitched well; we hit well. We made all the plays, and we came up with a couple big hits."
And Grossman, who grew up in the Houston area, came away with something more to remember. Grossman collected the ball from his first hit, and the ball that was the last putout of the game from the catch he made in center field. Porter also gave Grossman the lineup card.
"I'm here to play baseball and have fun," Grossman said. "I did what I know how to do, and that's play baseball.
"I can come out there and play hard every day and help them out."
Grossman was replacing Justin Maxwell, who is on the 15-day disabled list because of a broken left hand he sustained after being hit by a pitch in Tuesday's game from Seattle's Hisashi Iwakuma.
"He adds a dynamic to our club," Porter said of Grossman. "A little speed at the top of the lineup, and a guy that gets on base. We're pretty excited about him."
The Astros had a lot to be excited about Wednesday, as they had eight extra-base hits. The Astros collected 14 hits in all, including 11 off Seattle starter Joe Saunders (1-3), who allowed eight runs in five-plus innings.
"It was just a bad day; that's all I can really say," Saunders said. "Turn the page on it. Get 'em next time. Forget it easily. That's it. Bad days happen."
Laird collected career highs in hits (three) and RBIs (four). Cedeno went 3-for-4 and is hitting .333 on the season. Cedeno and Marwin Gonzalez, who are splitting time at shortstop, are a combined .309 with four homers and 13 RBIs.
While Saunders struggled, Harrell thrived, allowing one run and six hits with five strikeouts and two walks. His seven innings tied the longest by an Astro this season. Harrell has allowed two runs or fewer in four of his five starts this season.
"I'd gotten away from being aggressive; I need to attack more," said Harrell, who allowed the lone run against him on a double play. "Strike one was huge today. My goal was to attack and get strike one."
Carter's second-inning home run, his fifth of the season, opened the scoring. The homer to left field was a no-doubter.
"We scored a run early, and it puts you in the driver's seat as a pitcher," Harrell said. "All you got to do is throw strikes and get some people out. We hit the ball well today, from Cedeno to Carter and Robbie [Grossman] getting two big hits. I couldn't be any happier about the way we played."
Cedeno's home run in the fourth inning, his first of the season, gave the Astros a 4-0 lead. Grossman scored in the fifth as the Astros went ahead, 5-0.
Houston has homered in eight consecutive games and has 25 homers through 21 games. Last season the Astros had 11 home runs through 21 games.
Matt Dominguez's two-run single in the sixth gave the Astros a 7-1 lead and chased Saunders from the game. Laird's home run off Blake Beavan was part of a five-run sixth inning for the Astros in which they took a 10-1 lead.
With the win, Houston improves to 10-5 all-time against Seattle and 4-2 against the Mariners in 2013. In those six games, the Astros have scored 38 runs while hitting .336.
While there was plenty for the Astros to be pleased about Wednesday, Grossman was the talk of the clubhouse following the game: "He's a good player; I saw him in Spring Training," Carter said. "Robbie came up today and had a good game."
In his second at-bat, Grossman had a third-inning ground-rule double down the right-field line, and Grossman opened the fifth inning with a double down the left-field line. He scored on a double by Laird.
Grossman is only the second Astro to have two doubles in his Major League debut. James Mouton did it April 4, 1994, against Montreal.