Nick Franklin punctuated a seven-run second inning with his first career grand slam, spotting Seattle ace Felix Hernandez an early sizeable lead that wound up becoming a 12-5 rout of the Houston Astros at Minute Maid Park.
Dustin Ackley, Michael Saunders and Brad Miller each had two RBI for the Mariners, who swept this three-game set while extending their season-high winning streak to six games.
Hernandez (11-4) lowered his American League-best ERA to 2.43 after scattering four hits -- all singles -- and striking out seven over six innings.
"They made him work, but he did a good job of making pitches," Mariners manager Eric Wedge said of Hernandez.
Houston starter Jordan Lyles (4-4) was tagged for 10 runs -- nine earned -- on eight hits and two walks in four-plus innings.
"It was the snowball effect from the get go," said Lyles. "I was missing around the zone, wasn't quite hitting the target. Just a little bit off, really just came down to fastball command."
Seattle's second-inning surge came after shortstop Jake Elmore booted a potential double-play ball off the bat of Kyle Seager. Instead of the bases being empty, Kendrys Morales, who led off with a single, and Seager were aboard. Justin Smoak was the next batter and went down swinging, magnifying the error because that may have been the third out.
Things completely unraveled for Lyles from that point. Following a walk to Saunders that loaded the bases, Ackley and Miller supplied run-scoring singles around a hit batsman before Franklin drove a Lyles pitch out to right field.
Lyles gave up an RBI single to Morales in the fifth, then loaded the bases by hitting Seager in front of a Smoak single. Lucas Harrell took over on the mound and didn't allow a hit the remainder of the inning. However, the Mariners were able to score two more runs on a fielder's choice and an Ackley sacrifice fly.
Miller added an RBI single in the seventh to put Seattle up 11-0 and Saunders doubled home Brendan Ryan in the eighth to make it 12-1.
The Astros put up a four-spot in the ninth against the Seattle bullpen.
Hernandez is 6-0 in his last 10 outings since a loss to Texas on May 25 ... Ackley had three hits ... Saunders extended his hitting streak to 10 games ... The Mariners were 7-for-14 with runners in scoring position ... Following the game, the Astros designated infielders Carlos Pena and Ronny Cedeno for assignment and recalled shortstop Jonathan Villar from Triple-A Oklahoma City.