Not only had he pitched well to win in what was likely his final start of the season, he reached 200 innings for the first time in his career.
That this happened at the expense of the Mariners made it a bit sweeter.
"Pretty good for an average season," Keuchel said.
Keuchel (12-9) couldn't help himself in making a subtle reference to comments made earlier this year by Seattle manager Lloyd McClendon, who labeled him an "average pitcher."
On this night, he was anything but that.
The same could be said of the Houston hitters, who launched five home runs to tie a season high.
Chris Carter and Alex Presley hit two-run homers and Matt Dominguez and Carlos Corporan added back-to-back solo shots. Jake Marisnick had a three-run homer in the seventh inning as the Astros snapped a four-game skid.
The Mariners stayed one game behind AL wild-card leader Oakland and a half-game in back of Kansas City for the second slot. The A's and Royals both lost earlier in the day.
"It's a good night for all of them in the clubhouse because we needed a night like that," Astros interim manager Tom Lawless said.
Chris Young (12-9) was tagged for seven runs in three-plus innings.
Keuchel (12-9) pitched eight strong innings, striking out eighth. He also reached 200 innings in a season for the first time in his career.
"That's the only goal I had: 200 innings, because I want the team to rely on me to get it done," Keuchel said. "Just to be able to do that is very rewarding."
McClendon complimented Keuchel on his outing and attempted to clear the air regarding the comments he made earlier this year.
"Listen, everyone was up in a huff about what I said last time. I wasn't trying to downplay the kid," McClendon said. "He has average stuff. He knows how to pitch."
"He doesn't have David Price-type of stuff. That's just a fact. That's not a knock on the kid," he said.
Carter and Presley homered one batter apart in the first inning. Dominguez and Corporan connected off Young on consecutive pitches in the fourth.
It was Carter's 37th home run of the season, a career high. Nelson Cruz leads the majors with 39.
Dexter Fowler doubled and scored two runs for the Astros. Houston tied a season high for homers previously achieved April 6 against the Angels.
Jose Altuve got two hits, giving 218 this season. He tied Rod Carew for most by a second baseman since 1936. Carew reached the feat in 1974 with Minnesota. Charlie Gehringer had 227 with Detroit in 1936.
Young was tagged for seven runs and eight hits. He also threw two wild pitches.
Robinson Cano hit an RBI single for Seattle run in the third.
Marisnick homered off Erasmo Ramirez, who pitched four innings in relief.
HE'S A HIT
The Astros honored Altuve prior to the game for breaking the club's record for hits in a season. Craig Biggio, who had held the club record of 210 since 1998, took part in the ceremony at Minute Maid Park, which included Altuve being presented with a giant coupon good for 211 bottles of Minute Maid orange juice.
Mariners RHP Hisashi Iwakuma (14-8, 3.42 ERA), who is 6-3 over his last 10 starts, faces rookie RHP Collin McHugh (10-9, 2.66). McHugh has won his last six decisions and has allowed two runs or fewer in nine straight starts, the longest active streak in the majors.