Manaea worked seven innings of two-hit ball, out-pitching Felix Hernandez and propelling the A's to a narrow 2-1 victory at Safeco Field that allowed them to salvage one game of an otherwise disappointing series. They finished their road trip 3-5.
"I don't know where we'd be without him at this point," A's manager Bob Melvin said. "He's had a heck of an April for us, for sure."
Jed Lowrie provided the offense, jumping on a 3-0 offering from Hernandez in the first inning for a two-run homer following a one-out single off the bat of Marcus Semien, who was nearly wiped off the base path following a series of shenanigans.
Semien, attempting to steal second base, was caught in a rundown, except a balk was called on Hernandez -- then taken away, forcing both managers from their respective dugouts for clarification. Semien was allowed to remain on first, paving way for Lowrie's fourth homer of the season.
"They said that he jumped the gun on the call and that he did step off," Melvin explained. "They're trying to get it right, so it kind of worked out either way for us, based on the fact that Marcus was picked off. So if they're saying that they got the call wrong, then they can't call Marcus out. So I understand where they were going with it. He did step off and Jed ended up hitting a two-run homer, so I wasn't as upset about the call after that."
Manaea stranded a runner on third in the bottom half of the inning and was off to the races in chilly temps, his lone blemish a solo home run to Taylor Motter in the fifth. He proceeded to retire his final eight batters, needing just six pitches in the eighth and seven in the seventh to cap the impressive 89-pitch outing.
Closer Blake Treinen recorded the final four outs for his third save.
"Throwing everything for strikes and just relying on the defense," Manaea said. "Tried to get early outs and early contact and strikeouts when we needed it. That was the game plan today, and I felt like I was locating my fastball inside and out and keeping guys off balance."
Manaea, who fanned four and walked two, has completed at least six innings in three of his four starts, while no other A's starter has managed to do so once. He's yielded no more than two runs in any of them, surrendering just five through 27 2/3 innings for a 1.63 ERA. Other A's starters have combined for a 7.03 ERA.
"His ball's moving, especially with the slider and changeup now," Melvin said. "He can put you away with the heater and get some strikeouts, but you keep it on the ground, you keep everyone involved in the game and you're working quick, and he was economical. The [velocity] came down, but he's finding a way to pitch without a 95 mph fastball, and that means keeping some balls on the ground. He's learning how to pitch."
SOUND SMART Lowrie, who leads the American League with 23 hits, became the third Oakland player to reach four home runs this year, joining Matt Chapman and Khris Davis. No other team has more than two players with four home runs.
YOU GOTTA SEE THIS The Mariners threatened in the eighth when Mike Marjama worked a one-out walk against A's lefty Ryan Buchter, bringing speedy leadoff man Dee Gordon to the plate. Gordon plotted a bunt on the left side and sprinted toward first, but third baseman Chapman raced to the ball and sent a laser throw to first for the out -- just barely. Seattle challenged the call, but it stood, and Treinen entered and got an inning-ending flyout from Jean Segura. Chapman made a similarly outstanding play on a Gordon bunt in Saturday's game.
"I don't know how he makes that play, because you talk about probably the fastest guy in the league, and when he puts it down and deads it like that, it's almost impossible to get him," Melvin said. "And for him to come flying in there for a second time and get him, that's a huge part of the game, because now [Robinson] Cano comes in to play, you've got two runners on. That's a huge play. I'm not going to say you get used to a play like that, but I don't know that anyone else makes that play."
Added Lowrie: "It never ceases to amaze me with what he's capable of in the field. Hands, feet, arm strength. It's pretty special."
HE SAID IT "I'm really impressed with how he's executed. I think that's the biggest difference I've seen. The stuff is the same, but he's just executing on a much higher level, and when you got the combination of stuff that he does with the execution that you've seen in his first few starts, it's results you can expect." -- Lowrie, on Manaea
UP NEXT The A's will return to Oakland for a six-game homestand, beginning with three games against the White Sox. Right-hander Daniel Mengden, who is still seeking his first career home victory, will be on the mound in Monday's 7:05 p.m. PT opener at the Coliseum. Chicago will counter with right-hander Reynaldo Lopez, who has a 0.69 ERA in two starts this season.
Jane Lee has covered the A's for MLB.com since 2010.