SEATTLE -- Mike Zunino nearly left the yard Saturday night.

Literally.

Zunino hit a grand slam that nearly exited Safeco Field and drove in a career-high seven runs as the Seattle Mariners defeated the Tampa Bay Rays 9-2 for their sixth victory in their past seven games.

Zunino's fifth-inning blast went 441 feet down the left-field line and landed three rows from the top of the upper deck. It gave the Mariners grand slams in back-to-back games -- Taylor Motter hit one against his former team in the first inning Friday.

"When you barrel it up it takes care of itself," said Zunino, who also had a two-run double in the second inning and run-scoring single in the fifth, giving him a franchise record for RBIs in a game by a catcher. "I got some good pitches to hit today."

In 33 previous games this season, Zunino had one home run and five RBIs.

"It was a great night for 'Z' and I'm really happy for him with all the work he's put in," Mariners manager Scott Servais said."When the ball left the bat, I thought it had a chance to go out of the stadium. That's about as far as a ball is going to go in the upper deck."

Danny Valencia, who went 4-for-4, was on third base for Zunino's slam off Tampa Bay starter Alex Cobb (4-5).

"I had a good view. I was hoping it was going to get out of the stadium," Valencia said. "We need him. The guy works so hard. I know what it's like to look out at the scoreboard and not have the numbers you want to see."

Zunino was demoted to Triple-A Tacoma on May 5 after batting .167 with no homers and two RBIs in his first 24 games. It was the second straight season the former first-round pick was sent down.

He came into the game batting .184. He raised his average to .200 with his single in the fourth and finished at .206 by going 3-for-4.

"Now I have an idea of what I'm trying to accomplish," Zunino said. "It's nice to be able to step into the (batter's) box with confidence."

Nelson Cruz homered in the fifth -- his 100th as a Mariner -- on his bobblehead night.

The Rays' Corey Dickerson opened the game with a home run off Sam Gaviglio. It was Dickerson's 13th home run of the season and sixth leading off.

That was the only run Gaviglio (2-1) allowed in his five innings. Gaviglio, making his fourth career start, gave up four hits, didn't walk a batter and struck out six.

"Gaviglio did a nice job for us," Servais said. "It was nice to see the offense churning like that, it takes a lot of pressure off the pitching."

Seattle got 14 hits off Cobb in five innings. All nine runs against the right-hander were earned. He walked two and struck out three.

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

The Mariners took the lead with three runs in the second. Cruz led off by scorching a ball down the third-base line past Evan Longoria for a double. Cruz moved to third on a fly out to the right-field wall by Kyle Seager and scored on Valencia's line-drive single to left-center field.

Jarrod Dyson hit a two-out single to right field and Zunino followed with a two-run double into the gap in right-center. The Mariners nearly had one more run, but Zunino was thrown out at the plate by Rays outfielder Colby Rasmus on Ben Gamel's single to left to end the inning.

The Mariners made it 4-1 in the fourth as Valencia and Motter led off with singles and one out later, Zunino delivered a run-scoring single. Seattle also had a runner thrown out at the plate in that inning, as Motter was caught trying to score on a wild pitch.

Tampa Bay's Logan Morrison, a former Mariner, hit his 100th career homer in the ninth inning off Seattle's Edwin Diaz.

NOTES: Tampa Bay 3B Evan Longoria left the game early for the second consecutive night. Longoria was lifted Friday because of stiffness in his neck. He was 3-for-3 on Saturday before exiting with the Rays trailing by eight runs. ... Rays C Derek Norris was replaced in the middle of the eighth after hobbling off following a lineout to center field in the top of the inning. Manager Kevin Cash said Norris suffered back spasms and wasn't scheduled to play Sunday with an afternoon start. ... Mariners RF Ben Gamel, in only his second game in the leadoff spot for injured SS Jean Segura, was 3-for-4 with a walk. ... Rays RHP Erasmo Ramirez (3-0, 3.66 ERA) is scheduled to face Mariners LHP Ariel Miranda (5-2, 4.17) in Sunday's finale of the three-game series.