Vargas (7-5), who spent his past four seasons in Seattle, allowed one run in 6 1-3 innings and struck out five to earn the victory and the Los Angeles Angels defeated the Mariners 5-1 on Saturday night.
It was Vargas' first win since picking up the decision in an 11-3 victory over the Mariners on June 17.
"He had to pitch out of some jams, but when he had to, he got a couple double play balls," Angels manager Mike Scioscia said. "I thought Jason did a great job. It was great to see him get into the seventh and get to 100 pitches. He maintained his stuff. He pitched and I think that's when he's at his best."
The Mariners had multiple runners on base in the second and fourth innings, but came up empty each time as Vargas worked out of trouble.
In the fourth, Vargas walked Justin Smoak and Endy Chavez singled to put runners on the corners with no outs, but the Mariners left both runners stranded.
"We spread out some hits here and there, but we never really put anything together," Mariners manager Eric Wedge said. "You got to put more heat on them offensively. We didn't put a whole lot of pressure on them tonight. We got to make it more difficult for them than we did tonight."
Vargas said he didn't feel much different from his first two starts since returning from the DL, but this time he managed to get the result.
"I was just able to make pitches when the time came," Vargas said.
The Angels jumped on top early against Mariners starter Erasmo Ramirez (4-1). After a walk to Erick Aybar, Mike Trout hit his 22nd home run to give the Angels a 2-0 lead.
Chavez limited the early damage by robbing a would-be home run from Hank Conger in the second inning.
Ramirez and Vargas traded scoreless innings until Los Angeles managed to extend the lead in the seventh.
Grant Green singled and J.B. Shuck doubled to put two runners in scoring position with one out. Ramirez nearly worked out of the jam as Green was thrown out at the plate on a grounder to second, but Chavez dropped a fly ball that would have ended the inning and allowed Shuck to score to increase the lead to 3-0.
Humberto Quintero and Dustin Ackley led off the seventh inning with a pair of singles and Nick Franklin came to the plate to pinch-hit for Brendan Ryan.
With a 1-1 count, Franklin tried to call time, but it wasn't granted by plate umpire Ron Kulpa. Vargas appeared to hear Franklin's request while checking the runner at second base in his windup and stopped his motion. Kulpa called a balk and allowed both Quintero and Ackley to advance a base.
"When I heard it loud like that I just assumed it was the umpire but it wasn't," Vargas said. "That's all on me. I can't take that for granted."
Franklin grounded out to third to score Quintero and put the Mariners on the board for the first time in two nights and chase Vargas from the game.
Michael Kohn managed to work out of the jam. Despite hitting Kyle Seager with a pitch, Kohn struck out Brad Miller and Kendrys Morales to hold the Mariners at bay.
The Angels added two more runs off reliever Brandon Maurer in the eighth inning. After a single from Mark Trumbo, Kole Calhoun tripled to left-center field to score a run. Chris Nelson followed with an RBI single to drive home Calhoun and extend the Angels lead to 5-1.
Notes: Angels manager Mike Scioscia said RHP Garrett Richards anticipates making his next start after taking a liner off his right forearm in Friday night's win over Seattle. ... RHP Kevin Jepsen was placed on the 15-day disabled list after having emergency surgery Saturday in Seattle to remove his appendix. OF Collin Cowgill was recalled from Triple-A Salt Lake City. ... Mariners INF Nick Franklin pinch hit in the seventh inning and remained in the game at second base for the conclusion of the game. It was his first game action since suffering a gash in his knee during a game in Oakland Tuesday night that required stitches. ... C Mike Zunino took batting practice with the Mariners and the team plans to send him on a rehab assignment next week. Zunino has been on the disabled list since July 26 after suffering a broken bone in his left wrist.