Feierabend allowed four earned runs on seven hits in 7 1/3 innings, the longest outing of his short big-league career. He seemed to find his groove after allowing a three-run home run in the fourth inning to Victor Diaz -- the first of two home runs for Diaz -- and received plenty of help from Seattle's offense in the innings that followed.
He struck out five and walked one and received a standing ovation from the crowd when he exited the game with one out in the eighth inning.
"I couldn't believe that there was a chance that I was going to get my first Major League win," said a beaming Feierabend, who got a towel full of shaving cream in the face from closer J.J. Putz after the game. "It's very special."
So was his performance.
Faced with a shorthanded bullpen and a 4-1 deficit, Feierabend continued to patiently deliver his pitches and record crucial outs.
He knew he had to go deep in the game, but never worried that it would become an issue.
"You try not to think about that," Feierabend said. "As a starter, you don't want to think about your pitch count, and try not to worry about going later in the game because that's when you're going to start making bad pitches when you should be executing them."
It didn't take long for his teammates to respond.
Second baseman Jose Lopez keyed Seattle's fourth-inning outburst, slamming a three-run double off the top of the left-field wall. Lopez, whose shot was inches away from being a grand slam, finished the game 4-for-5 with three RBIs and two runs scored.
"I was looking for a breaking pitch, and I hit it good," Lopez said. "I thought I had a grand slam. ... I almost got it."
The hit, which put the Mariners up 6-4 at the time, was more than enough breathing room for Feierabend, who settled down in the fifth.
"He kept his poise," said bench coach John McLaren, acting as manager until Mike Hargrove returns Monday. "He made a bad pitch, he gave up the home run and we got behind. Sometimes young kids get frustrated and start overthrowing. ... He looked like a seasoned pro out there."
Even after the Mariners grabbed the lead, they continued to drive in runs, a promising sign for an offense that had been struggling early in the season. The win marked the third time in four games Seattle scored eight or more runs in a game.
The Mariners roughed up Texas starter Robinson Tejeda, scoring eight runs on eight hits in just 5 2/3 innings against him, and are 11-2 when scoring eight or more runs.
Even more importantly, they kept pace with the Angels, who came from behind to beat the Orioles in the ninth inning. Seattle's win keeps it 5 1/2 games out of first place. The Mariners start a three-game series with Baltimore on Monday.
"We know the Angels are playing well," McLaren said. "Hopefully they cool off, and we'll catch them."
Right fielder Jose Guillen was 3-for-4 with three RBIs, and shortstop Yuniesky Betancourt extended his Major League-leading hitting streak to a career-high 15 games. Left fielder Raul Ibanez extended his hit streak to 11 games.
But the day belonged to Feierabend, who, at least on Sunday, looked like he belonged in the Mariners' clubhouse.
"It's incredible," Feierabend said with an ear-to-ear grin. "I don't know how to describe it except for incredible."