SEATTLE -- Mike Zunino had this weekend’s series earmarked all season, hoping that a return to the setting of his most successful days would help him maintain offensive momentum in his upward-trending August.

Zunino’s homecoming to T-Mobile Park, where he played for six seasons, certainly looked as if it helped. The former Mariner crushed a three-run homer that propelled the Rays to a 5-4 win over Seattle, their 11th in their past 14 games, which helped Tampa Bay build a 1 1/2 game lead over Oakland for the second American League Wild Card spot after the A’s lost to the White Sox.

• Box score

“That one was a good one,” Zunino said. “It's bittersweet in a sense, but it's time to close a chapter and open up a new one. It's nice to be back here and helping this team in any way I can and continue this road trip off on the right foot.”

Zunino’s production uptick comes as a welcome sign for a Rays club that had three everyday players -- Brandon Lowe, Tommy Pham and Yandy Diaz -- out of Saturday’s starting lineup. And Zunino’s eighth homer proved to be a reflection of how the club continues to find ways to win. In a sample of just six games this month, Zunino is slashing .313/.421/.875, with three homers, after posting a .165/.227/.300 mark over 216 plate appearances from March-July that led to diminished playing time.

Eyeing the season’s final seven weeks, Zunino believes he’s rediscovered mechanics within his swing that were a casualty of the quadriceps injury that he sustained earlier this season.

“I just got myself in a better position to hit,” Zunino said. “I was feeling good before I got hurt. I just never got quite back to what I was feeling then. I think I finally stumbled across something that's working after a few attempts of changing my swing. I'm hoping that's what it is. I'm feeling more balanced at the plate and able to get my swing off easier.”

Tough-luck inning ends Morton’s night

All-Star righty Charlie Morton was solid, but perhaps not at the elite level that had him earning consideration for the AL Cy Young Award. Morton picked up his 13th win while allowing a season-high nine hits that led to four earned runs. He also struck out 10 and walked zero.

Morton likely would’ve pitched into the seventh, but he wound up giving up a pair of singles and let a run score after throwing a wild pitch that ballooned his pitch count from 76 to 100 and ended his night. The Mariners also benefited from putting more than half of their 17 balls in play against Morton.

“I try to judge myself on how I threw the ball,” Morton said. “How did I throw? How was my stuff? How was my execution? I would say it was better than the results, than the macro results. But when I'm looking at that start, when I'm sitting there in the dugout and clubhouse, the reality is that I gave up a bunch of runs and a bunch of hits.”

Over his past five starts, Morton has a 5.04 ERA, well above the 2.35 mark he posted over his first 20, which was the AL’s lowest.

When Morton doesn’t have his best stuff, the Rays’ bullpen has largely backed him, and they did again Saturday with three hitless innings, headlined by Nick Anderson striking out the side in the eighth with a flash of the pure stuff the Rays are raving about.

Taste of their own medicine

The Rays won for the first time in four games this season against an opener, outlasting Seattle’s tandem of Matt Wisler and bulk-innings pitcher Tommy Milone, whose five runs came via homers, to Zunino, Kevin Kiermaier and Avisail Garcia.

Despite pioneering the strategy last season, Tampa Bay has only faced a copycat six times, and it will face another Sunday. The Rays also squared off against an opener in last Sunday’s 4-3 loss to the Blue Jays, between Wilmer Font and righty Brock Stewart.

“Facing different guys, it's harder,” Kiermaier said. “That's why teams do it. The analytical department, people do their research. The numbers speak for themselves. Not crazy different, but I think it's a trend that you're going to see for a while because we had a lot of success doing it last year and now there's a ton of teams doing it.”