SEATTLE — After a brief demotion to the minor leagues, Mike Zunino appears to have regained his hitting stroke - and then some.

The Seattle catcher hit his first grand slam and drove in a career-high seven runs to power the Mariners to a 9-2 victory over the Tampa Bay Rays on Saturday night.

Zunino, sent to Triple-A Tacoma for two weeks in May after struggling offensively, hit a two-run double in the second, an RBI single in the fourth and capped a five-run fifth with his slam that put the Mariners up 9-1.

"There's a level of confidence and it's much needed," said Zunino, who had five RBIs in 103 at-bats before Saturday. "And now I can just sort of look for my pitch now and attack it. I don't have to worry about where my body is or doing anything like that. It's just nice to step in the box and feel like you can hit."

Rookie right-hander Sam Gaviglio (2-1) allowed one run — a homer by Corey Dickerson to lead off the game — and four hits in five innings. He struck out six and walked none in his fourth start since being called up May 10.

"He's hot right now and I made a little bit of a mistake and he took advantage of it," Gaviglio said. "I felt good with my warmups and I was feeling good on the mound today and I didn't want it to affect me."

Alex Cobb (4-5) was rocked for a career-high nine runs and 14 hits in five innings.

"I thought Alex battled, but you could tell that he just wasn't locating the baseball like we've seen him in the past or like he's capable of," Rays manager Kevin Cash said. "And Seattle burned him a little bit."

Nelson Cruz had three hits, including a solo homer, and Danny Valencia had four singles and scored three times for the Mariners, who won for the sixth time in seven games.

The Mariners erased a 1-0 deficit with three runs in the second on Valencia's RBI single and Zunino's two-run double to the gap in right-centre.

"It was a good sign when he hit that ball to right-centre to start off, a big double early in the game," Mariners manager Scott Servais said. "It just got better after that."

Seattle made it 4-1 in the fourth on singles by Valencia, Taylor Motter and Zunino. The Mariners failed to add on when Motter was out at home attempting to score from third on a ball that initially got away from catcher Derek Norris.

Cruz got Seattle's five-run fifth started with his 13th homer, a one-out solo shot to left. The Mariners loaded the bases on a single by Valencia, a walk to Motter and Jarrod Dyson's bunt single. Zunino then drove a 1-2 pitch into the upper deck in left, estimated at 441 feet.

"I'd seen all of his pitches already in the zone and I was just able to get that splitter up," said Zunino, who was hitting .167 when he was sent down, but has raised his average to .206. "I just didn't try to do too much. I was just trying to drive the ball and I was able to get a good pitch."

Logan Morrison hit a solo homer in the ninth for the Rays, his 16th and 100th of his career.

VALENCIA HOT

Valencia has reached base eight straight times in the last two games, including seven consecutive hits. He walked in his first at-bat in Friday's 12-4 victory over the Rays, and then added a three-run homer, a single and a double en route to five RBIs. He singled in all four at-bats on Saturday to raise his average .276. Valencia was hitting .188 in his first 22 games. Since May 2, he is hitting .339.

TRAINER'S ROOM:

Rays: 3B Evan Longoria, who left Friday's game with neck stiffness, was back in the lineup, batting third. Longoria had three singles Saturday before coming out after the sixth inning. ... Norris limped off after flying out to centre field in the eighth and was replaced behind the plate by Jesus Sucre. "Back spasm," Rays manager Kevin Cash said after the game. "It's more in the muscle. We expect he'll be OK. Obviously, he's not going to play tomorrow, but he should be OK after that."

Mariners: SS Jean Segura, placed on the 10-day DL on Friday (right high ankle sprain), is optimistic for a quick return. "I don't think it's going to take a month, maybe a couple weeks," Segura said Saturday, wearing a boot on his right ankle. "We'll see how it feels the next couple of days." Segura was injured Thursday on a slide into second when he tried to advance on a sacrifice fly. ... OF Mitch Haniger (strained right oblique) was OK a day after taking batting practice Friday and could begin a rehab assignment next week. ... RHP Hisashi Iwakuma (right shoulder inflammation) threw a simulated game Saturday. "I think where he's at mechanically, not quite consistent in his release point yet," Servais said. "It's a step in the right direction, to get hitters in there. You dial up the intensity a little bit and sometimes you get a better read on where you're at."

UP NEXT:

Rays: RHP Erasmo Ramirez (3-0, 3.66) starts the finale of the three-game series Sunday at Safeco Field against the Mariners. Ramirez, making his fifth start, lasted just 2 1/3 innings in his last start, allowing four runs on six hits after pitching an inning in relief the previous day.

Mariners: LHP Ariel Miranda (5-2, 4.17), originally slated to start the season at Triple-A, has provided much-needed reliability to the injury-ravaged rotation. He has allowed only six earned runs in 22 innings in his last four starts.