"I felt pretty good today," Hernandez said. "All my pitches were working, I was down in the zone, I was throwing strikes. That's me right there. That was the best game I've thrown this year."
Best of all, the Mariners rewarded him with the much-deserved win when Jaso delivered his team-leading seventh game-winning RBI of the season with a single to right after Wells had doubled off reliever Scott Atchison.
Seattle had scored just four runs over its previous four games and didn't get to Boston's pitching staff until Jaso punched his single to right and Wells touched the plate after catcher Jarrod Saltalamacchia couldn't handle the throw to the plate from Cody Ross.
"I knew Cody was going to make a great throw, and he did," said Saltalamacchia. "It was right on the money. I've just got to do a better job of holding onto it in a big situation like that."
"He had to make a quick grab-and-tag and luckily I got in there," said Wells, who also contributed an excellent sliding catch down the left-field line in the eighth to help preserve Hernandez's gem.
The Red Sox, who had won nine of their last 11 games, managed just five singles off Hernandez, who threw a season-high 128 pitches in what manager Eric Wedge called "a warrior performance."
Jaso then delivered after Atchison had intentionally walked Justin Smoak, hitting what he said was a cutter/slider from the right-hander.
"I've faced him before and that's his go-to pitch -- and it's a good one, too," Jaso said. "He's got me out on it more than I've hit it. He just left it over the plate a little too much. I'm glad I went up there in swing mode and not looking to see a lot of pitches, just looking to drive in a run. So I didn't miss it."
Hernandez survived a tough ninth of his own to record the shutout. David Ortiz knocked Hernandez down with a single back up the middle with one out and Hernandez issued his first walk of the night to Saltalamacchia to put runners on first and second.
Adrian Gonzalez then lifted a deep drive to center that Michael Saunders tracked down and Hernandez got Will Middlebrooks to pop out to second to maintain his shutout.
Wedge said he left the game in Hernandez's hands despite the high pitch count, which tied the most of his career.
"It was going to be him," Wedge said. "As fate would have it, they started fouling balls off and going deep counts and I've got to glue my you-know-what to the bench to stay there. But I was going to give him every opportunity to finish that off, because he had earned it, he's strong, he works hard, he's experienced and it paid off for us."
Hernandez racked up double-digit strikeouts in back-to-back games for the first time in his career after setting down 10 Padres on Saturday in San Diego.
The Mariners didn't make any noise against Boston starter Franklin Morales either, totaling three singles in seven scoreless innings against the lefty.
Morales, making just his third start for the Red Sox, didn't allow a runner past first until Smoak singled and took second on a wild pitch with one down in the bottom of the seventh.
Smoak moved to third when Dustin Ackley hit a slow dribbler down the first-base line, with Gonzalez charged with an error when Morales' flip to first went off his glove. But that rally died on Brendan Ryan's groundout to third.
Franklin Gutierrez reached on a single leading off the fourth for Seattle's first hit, but he was knocked out of the game when Morales hit him in the right side of the face with a pickoff throw that got past the glove of Gonzalez.
Gutierrez was down on the ground for nearly two minutes before being replaced by Saunders. That stood as Seattle's only hit until an infield single by Kyle Seager in the sixth. Gutierrez has a mild concussion and will be re-evaluated on Friday, said Wedge.
Hernandez hit a rough patch over a six-start stretch from April 11 to May 12 when he went 1-4 with a 6.37 ERA, but he's certainly squared himself away since. In his past three starts, Hernandez has allowed just two runs and 17 hits in 23 innings.
Hernandez hasn't given up a run since the first inning of his last start in San Diego, a string of 15 straight scoreless frames.
"I'm throwing more strikes," he said. "I was getting ahead of hitters and mixing in breaking balls. The fastball has more life right now, so I feel pretty good."
And the Mariners were happy to get the win for their ace.
"I wanted to do it so bad for him," said Wells. "He pitched his tail end off. We came through with some big plays for him, but that was an unbelievable performance to watch."