SEATTLE -- Marco Gonzales , who opened the season as Seattle's fifth starter, continued delivering top-of-the-rotation results on Saturday as the Mariners topped the Rays, 3-1, and moved into a tie for first in the American League West.

The 26-year-old lefty fired 6 2/3 innings of one-run ball and is now 6-3 with a 3.38 ERA, allowing just one earned run over 26 innings in his last four starts. The former Cardinals' first-round Draft pick allowed five hits with two walks and six strikeouts.

Gonzales' pitching is one of several reasons the Mariners are turning into one of the surprising stories in MLB this season as Seattle has won 12 of its last 15 games and a share of the AL West lead with Houston at 36-22.

The last time Seattle led the division this far into a season was Aug. 26, 2003, and the 36 wins are the fourth-most in franchise history through 58 games, trailing only the 2001-03 teams.

The Mariners are thrilled to be in the hunt with Houston atop the division and they now have a 5 1/2-game lead over the third-place Angels in the AL West, but manager Scott Servais acknowledged it's far too early to be celebrating.

"It doesn't mean anything because it's June 2. Come talk to me on Oct. 2," Servais said. "We have a lot of ball left to play. But what we've done is put ourselves in a great situation to have an exciting summer and finish to the season. Our guys are looking forward to it."

Gonzales, acquired last July from the Cardinals in a trade for outfielder Tyler O'Neill , has become a cornerstone of that effort.

"I love pitching for this team," Gonzales said. "We just love playing for each other right now. We're all just rallying around each other, and it's a lot of fun to be out there."

Ryon Healy hit his ninth homer of the season for the Mariners, a solo shot off reliever Wilmer Font leading off the sixth. Seattle scored twice off starter Chris Archer in the third on an RBI single by Nelson Cruz and a run-scoring double by Kyle Seager .

Three Mariners relievers took care of business after Gonzales' departure, with ex-Rays closer Alex Colome delivering a perfect eighth against his former team and Edwin Diaz finishing things off for his MLB-leading 20th save.

The Rays' only damage against Gonzales came on an RBI double by Wilson Ramos in the sixth that narrowly missed being a two-run homer as it deflected off the yellow line atop the wall and stayed in the field of play.

Tampa Bay fell to 28-29 and has lost nine straight games to the Mariners at Safeco Field, dating back to the start of 2016.

MOMENTS THAT MATTERED

Gonzales helped himself out of trouble in the fifth when he picked Rob Refsnyder off first with a snap throw after Refsnyder had reached on a one-out single. It was Gonzales' third pickoff in the past two games and fifth of the season, tying him with Julio Teheran of the Braves for the most in the Majors. That out loomed large when Gonzales hit Carlos Gomez and gave up a single to Christian Arroyo on a hit that either would have scored a run or left the bases loaded with one out. Instead, Gonzales got Jesus Sucre to fly out to left to preserve a 2-0 lead.

"Marco is really athletic," Servais said. "He was a two-way guy in college who played first base when he didn't pitch. You can see it. He can do some different things. The pick-off move tonight was awesome. He picked a couple guys off second his last time out. It's really valuable and really helps. He's one of those left-handers who is real athletic and he takes advantage of it."

SOUND SMART

The Mariners are 14 games over .500 for the first time since being 80-66 after 154 games in 2014.

HE SAID IT

"He's come a long ways from where we were in April. Everybody questioned when is this guy going to be able to get through a lineup three times. It's a process. You have to be patient with young guys. We certainly have been with Marco and it's paying off. We're seeing the confidence grow and how he's able to execute pitches that third time through the lineup." -- Servais, on Gonzales, who has pitched six-plus innings in seven of his last eight starts

MITEL REPLAY OF THE DAY

The Mariners had a double-play groundout by Dee Gordon reversed in the sixth when Servais successfully challenged the out call at first. Gordon clearly beat the relay throw from Arroyo, but was ruled out until a quick review overturned the call. Gordon instead was credited with a fielder's choice grounder and the Mariners had runners on first and third. That allowed Gordon to steal his second base of the game, but didn't result in any runs as Jean Segura grounded out to end the inning.

UP NEXT

Felix Hernandez (5-4, 5.83 ERA) closes out the series against Rays lefty Blake Snell (7-3, 2.56 ERA), a Seattle native making his first Major League start at Safeco Field. Hernandez has struggled with slow starts recently and is 1-2 with a 7.16 ERA over his last five outings, but he's always performed well against Tampa Bay (8-2, 1.94 ERA in 16 starts).