The Mets dropped their third straight after winning eight of nine and have managed a total of three runs in the losses.
"We got a hit every inning, but you need a bunch of them. Unless you're walking, those singles don't do much if you don't bunch them together," manager Terry Collins said. "They got a couple guys on and they'd get a big hit. But we'd get a guy on and we just couldn't get an extra-base hit or anything to get a guy in."
Kyle Seager drove in two runs, Mike Zunino homered into the second deck at Safeco Field and Dustin Ackley stole a home run with a leaping catch at the wall as Seattle improved to 8-2 all-time against the Mets.
Roenis Elias (8-8) threw 5 1-3 innings before leaving with cramping in his left forearm. Seattle's bullpen was stellar the rest of the way, helped by Ackley's outstanding grab to rob Travis d'Arnaud of a home run in the sixth.
Ackley didn't know he made the catch until hitting the ground.
"I knew I felt something. I didn't know if I felt it hit off my glove or go in the web, but when I came down is when I knew I had it," he said. "I was like, 'Well something is in there.'"
Seager had RBI singles in his first two at-bats and Zunino hit his 14th homer of the season, an estimated 415-foot shot off Niese (5-5) into the second deck in left field.
Ackley added an RBI double in the eighth, part of a three-hit night.
Niese was activated from the disabled list before the game. He hadn't pitched since leaving in the first inning July 4 against Texas when he was struck in the back by Alex Rios' line drive. He was placed on the DL two days later with a left shoulder strain.
Niese's streak of 21 straight starts giving up three earned runs or less was snapped when Willie Bloomquist collected his third hit, an RBI double in the fourth inning for a 4-1 Seattle lead. Niese allowed 11 hits and struck out six in six innings.
"I knew you guys were going to ask about that. It's great, but I really wasn't thinking about it. It really doesn't matter," Niese said. "I was just trying to hit my spots today and I really didn't on a consistent basis. Maybe I can start another streak."
Wright had an RBI single, but the Mets' only other run came on second baseman Robinson Cano's error in the ninth that allowed Juan Lagares to score.
The other chance New York had was in the sixth after Elias left with cramping in his arm. Dominic Leone took over and was immediately greeted by a deep drive from d'Arnaud. Ackley found the left-field fence, got just enough elevation to get his glove over the wall and made the catch in the webbing of his glove.
"I mean, that ball gets out of the ballpark, it changes the momentum completely," Collins said. "So it was a great catch."
NOTES: Wright's debut came on July 21, 2004, at Shea Stadium against Montreal. He went 0 for 4 while batting seventh in a 5-4 Mets win. Wright said the memories of being at Triple-A Norfolk the night before, getting notified of his call-up and arriving at the stadium remain vivid. His teammates treated Wright to dinner on Sunday night when they arrived in Seattle. Wright said the dinner became more of a roast. ... Seattle picked up its 22nd win vs. left-handed starters, most in baseball. ... Niese last allowed more than three earned runs Sept. 7, 2013, at Cleveland. ... New York OF Chris Young left in the eighth with a cramp in his calf. ... Seattle optioned 1B Justin Smoak after the game to clear a roster spot for Tuesday's starter, Erasmo Ramirez.