The teams split the brief two-game set in Seattle but will be right back at it Wednesday in San Diego for two more games as the "natural rivals" conclude their season series.
Gyorko hit a two-run shot in the fourth inning off Seattle starter Brandon Maurer, his sixth homer of the season. Amarista followed with a solo shot an inning later, and the Padres knocked out Maurer (2-7) with three runs in the sixth as they won for just the second time in the past seven games.
Gyorko set a Padres rookie record for homers in one month with his sixth in May.
"It's always been that way. You get your timing right for that certain amount of time and you see the ball well," Gyorko said. "You get your hits; you're going to go through slumps at times. It's all about getting that timing right and putting a good swing."
San Diego got a major momentum swing in the bottom of the fourth when Seattle's Michael Morse was thrown out at home plate trying to score from first on Michael Saunders' double.
The relay was perfect from Amarista in center to Everth Cabrera at shortstop and then to Yasmani Grandal, who had plenty of time to get the tag on Morse.
As if getting cut down at the plate wasn't bad enough, Morse left the game after straining his right quadriceps on the play.
But what Volquez did after Morse was thrown out was just as important. Saunders was left stranded at third, and Volquez retired the next eight and then 12 of 14 batters before leaving with two outs in the eighth inning. The only hit Volquez allowed after Saunders' double was Kyle Seager's two-out single in the eighth.
"I think I'm a little bit different pitcher when my breaking ball is working because I know I can throw my breaking ball for a strike, behind in the count, ahead in the count," Volquez said.
Volquez faced trouble in the second inning when Seattle loaded the bases with no outs. He got Nick Franklin to hit a grounder to first, and Kendrys Morales was forced out at home. Jesus Sucre hit a sacrifice fly to score Morse with Seattle's only run, and Volquez got a fly out from Brendan Ryan to end the threat.
Volquez gave up four hits, struck out five and walked three.
"I feel my curveball was better than my changeup today," Volquez said. "Just wanted to be aggressive and keep the ball down. I think I only get in trouble that one inning, the second inning. After that I was good."
Grandal returned from his 50-game suspension for San Diego and immediately was placed in the starting lineup. He got his first hit of the season when he dumped a sinking liner into left as part of the Padres' three-run sixth.
Seattle got lefty reliever Charlie Furbush up in the bullpen late, and Maurer was forced to face Mark Kotsay and Will Venable, both lefties. Kotsay lined a single into left-center to score Yonder Alonso and Grandal. Venable nearly cleared the bases with his drive, which was was caught at the wall by Endy Chavez.
Furbush took over and immediately walked Cabrera. He got pinch hitter Chris Denorfia to ground weakly to second, but Franklin -- making the first start of his career -- mishandled the routine ground ball, allowing Gyorko to score the third run of the inning.
Maurer was lifted after 5 2/3 innings, giving up nine hits and five earned runs.
"I think I started throwing in a pattern, throwing the same pitches in the same counts," Maurer said. "They were sitting on them."
Padres IF Logan Forsythe, on the 60-day disabled list with plantar fasciitis in his right foot, is expected to begin a rehab stint at Triple-A Tucson later this week. Black said Forsythe would play second base, third base and shortstop. ... Seattle SS Brendan Ryan had his six-game hitting streak snapped. ... The Padres are 7-3 in their past 10 games in Seattle.
Copyright by STATS LLC and The Associated Press
SEATTLE, WA - MAY 28: Second baseman Nick Franklin #20 of the Seattle Mariners throws home during infield...