It was Houston's second straight win over the Mariners. Houston's series victory put a damper on Seattle's Wild Card hopes, but it has uplifted the Astros (69-87), who finished 38-43 at home, 14 more wins than a year ago.
"Good way to end the season at home," said Houston interim manager Tom Lawless. "Winning breeds confidence. Confidence breeds better at-bats.
"Up and down the lineup, the at-bats are really good and you're going to score some runs. It's a good feeling in that dugout to beat them two out of three."
Houston starter Collin McHugh (11-9) pitched six effective innings. But it was the offense that really got untracked for the second consecutive game.
In Houston's 10-1 win on Saturday, the club homered five times.
On Sunday, the Astros had 14 hits. Alex Presley had three hits, including a two-run go-ahead single in the fifth inning that chased Seattle starter Hisashi Iwakuma. For the second straight game, Jake Marisnick homered. His three-run homer in the seventh increased the lead to 7-3.
Marisnick, Gregorio Petit and Jonathan Villar -- the bottom third of the lineup -- each had two hits.
Oh, by the way, Altuve had his customary game. The fan favorite went 2-for-4 with two runs to increase his American League- and Major League-leading batting average to .345.
"When you're not in there every day, you want to make the most of the times you get in," said Presley. "We're just having fun watching Altuve get hits.
"We're going to feed off his hits. It's been a blast this homestand. As a team and watching him play. He's unreal, and he deserves all the praise he's been getting."
Altuve, who broke Craig Biggio's franchise-record of 210 hits in a single season earlier this month, is demolishing that mark. He has 220 hits with six games remaining. The Astros conclude their season with three games against the Rangers in Arlington, followed by three games in New York with the Mets.
In Houston's three-run fifth, Altuve's 219th hit was an RBI double that closed the gap to 3-2, He has the most hits by a second baseman since 1936, when Charlie Gehringer of the Tigers had 227. Altuve was intentionally walked in the sixth and added his 220th hit on an infield single in the eighth.
Altuve recorded his franchise-leading 68th multi-hit game, the most since Ichiro Suzuki had 69 for Seattle in 2010.
Lawless, Altuve's teammates and the fans in Houston are appreciating the record-setting numbers. That's why Lawless brought Altuve in from the field and to the dugout during the ninth. So the fans could show Altuve how much they've enjoyed watching and following him in 2014.
"We talked about it in the dugout, that it would be a nice tribute to him the way he's played here all year long," said Lawless. "The magical year that he's had. We decided to let the fans just appreciate him a little. That's why we took him out of the game.
"He's the catalyst of the ballclub. When he gets on, things happen. He has 220 hits. That's unheard of, for him to do it and continue to do it just about every game."
Altuve was warmed by the fans' ovation.
"I want to thank the fans for supporting the team," said Altuve.
The Astros are much improved from last season when they lost a franchise-worst 111 games, including their final 15.
"I think we're going to come back next year and do what we've been doing lately," said Altuve. "And if we play that way, we're going to be in the payoffs."
Altuve's play and leadership is a big factor for the Astros' improvement.
"He's a competitor, he's a baseball player, and he wants to win," said Lawless. "That's the character we are trying to change. We want baseball players that want to win. There's a lot of baseball players that don't want to win. Mr. Altuve is leading the pack on our team and we're going to follow him."
In addition to Altuve's contributions, the Astros have been receiving strong starting pitching of late. McHugh was no exception. In six innings, the right-hander allowed three runs and four hits with six strikeouts and one walk. He retired the side in order in three of his first four innings.
After Seattle had taken a 3-1 lead in the top of the fifth on Michael Saunders' two-run home run off McHugh, McHugh struck out four straight and five of the next six.
"McHugh has pitched great all year and we seem to face him in every series," said Saunders.