HOUSTON -- The last time Felix Hernandez had a 7-0 lead, everything fell apart for Seattle's ace.
This time around things were much different.
Nick Franklin hit his first career grand slam in Seattle's big second inning to back up a scoreless start by Hernandez, and the Mariners rolled past the Houston Astros 12-5 on Sunday for their season-best sixth straight victory.
Franklin's slam, Seattle's fifth this season, came off Jordan Lyles (4-4) in a seven-run second.
Hernandez (11-4) scattered four hits with seven strikeouts over six innings to lower his AL-leading ERA to 2.43. He is 6-0 in his last 10 starts and hasn't lost since May 25.
The Mariners were up 7-0 in the third inning against the Angels on June 20 before Hernandez was tagged for a season-high seven runs over the next three innings as Los Angeles rallied for a 10-9 win.
"I'm sure it was in the back of everyone's mind, but he was a different animal today," Seattle manager Eric Wedge said. "He's one of those guys, it might happen once, but it's not going to happen again. I thought he did a good job against them. They made him work. But he did a good job and made pitches."
Hernandez said he didn't think about that game against the Angels, he simply appreciated getting so much run support early.
"Oh yeah, man, it's fun to pitch like that," he said. "The last few weeks we've been scoring a lot of runs. We've just got to continue to do that and we're going to win a lot of games."
Lyles yielded eight hits and 10 runs, with a career-high nine earned, in four-plus innings to lose his third consecutive decision
"It snowballed," Lyles said. "From the get-go, I was missing around the zone. I wasn't quite hitting targets. I was just a little bit off. It really came down to fastball command."
The Mariners piled up 13 hits, a day after managing just one in a 4-2 win.
Wedge liked that his team continued to pad the lead after going up by seven early.
"A lot of times you'll see that: You get a big lead and you don't do anything the rest of the game," Wedge said. "I thought our guys did a good job of staying hungry."
Hernandez didn't allow a runner past first base until the fifth when Justin Maxwell reached on an error by Miller at shortstop and went to second on a wild pitch. Maxwell advanced to third on a one-out single by Jake Elmore, but Hernandez left Houston empty-handed when Jose Altuve grounded into a double play.
Saunders drew a one-out walk to load the bases before an infield single by Ackley made it 1-0. A second run came home when Lyles plunked Henry Blanco with a pitch.
Miller's RBI single pushed the lead to 3-0 before the grand slam by Franklin, off to an impressive start in his rookie season.
"It was definitely a great bounce-back from yesterday and only having the one hit," Franklin said of jumping on Houston early. "But at the same time, we've been swinging it well and it was just one of those adjustment periods we had to go through and get back after it the next day."
Lyles retired Raul Ibanez before finally escaping the inning when Morales came up again and grounded out.
Lyles settled down after that and retired six of his next seven batters. Things started going awry again in the fifth when Ibanez led off with a double before an RBI single by Morales made it 8-0. Lyles hit Seager with a pitch and was chased by Justin Smoak's single.
Saunders grounded into a force out to add another run and the Mariners went up 10-0 on a sacrifice fly by Ackley.
Miller pushed the lead to 11-0 with an RBI single in the seventh, and Saunders extended his career-best hitting streak to 10 games with an RBI double in the eighth.
The Astros got a run-scoring single from Altuve in the seventh and tacked on four runs in the ninth to make it 12-5.
Houston opens a series with the Athletics on Monday when Dallas Keuchel (4-5) opposes Tommy Milone (8-8). ... The Mariners return home to begin a series against Cleveland, with Aaron Harang (4-8) scheduled to pitch against Ubaldo Jimenez (7-4). ... It was the fourth time this season the Mariners scored 10 runs or more and the second in this series. ... After the game, the Astros designated 1B-DH Carlos Pena and SS Ronny Cedeno for assignment and called up SS Jonathan Villar from Triple-A Oklahoma City.