SEATTLE -- The book is already out on Seattle rookie Carlos Peguero: Don't give him many fastballs.

Tampa Bay starter James Shields tried to follow that thinking, peppering Peguero with changeups and curveballs. Shields just happened to do it on a night where he wasn't sharp and Peguero showed he can make adjustments.

Peguero hit two of Seattle's season-high four home runs, all four off Shields, and ace Felix Hernandez cruised through seven innings to lead the Mariners to an 8-2 victory over the Rays.

Peguero hit a three-run homer as part of Seattle's five-run second inning, then added a solo drive in the fourth. And both came on off-speed pitches where Peguero showed just how powerful a swing he possesses.

"They throw me a lot of off-speed pitches and it's making an adjustment and being patient and waiting on it and putting a good swing," Peguero said.

Justin Smoak and Jack Cust also hit solo shots for the Mariners, who roughed up Shields (5-4) for a season-high seven earned runs. Cust's homer was his second of the season and first at Safeco Field, while Smoak homered for the third time in the Mariners current homestand.

But this night was about Peguero, who snapped an 0-for-14 slump when he homered off Shields in the second.

"He's strong. He has tremendous raw power. I felt like the previous game, I know he's been struggling a bit, but they were better, they were more under control," Seattle manager Eric Wedge said. "That's where he needs to be. He doesn't need to try and get more. It's already in there."

How many more chances Peguero gets in left field remains a question. The rookie was hitting only .169 entering Thursday night, but Wedge found it hard not to give the youngster an opportunity because of the power he brings to Seattle's lineup.

Peguero showed a measure of growth in his first at-bat, which ended with a 421-foot drive to right-center. Peguero was fooled early in the count on a changeup from Shields, but made an adjustment and waited on the off-speed pitch, driving it well into the seats.

In his second at-bat, Peguero again caught Shields making a mistake with an off-speed pitch. But instead of trying to pull Shields' hanging curve, Peguero went with it and drove it out to left-center. When Peguero came to the plate in fifth, fans in a special section devoted to Hernandez in the left field corner started chanting "Carlos! Carlos!" even though Peguero struck out for the 23rd time in 62 at-bats.

Peguero wasn't the only Mariners bat who showed something at the plate. Chone Figgins came through with an RBI single in the second after being benched for two games due to a prolonged slump.

With eight runs on the board, Hernandez (6-4) must have felt as if he got a month worth of run support. The AL Cy Young champ struck out 11 -- his third time this season with 10 or more -- and gave up just five hits in seven strong innings.

The matchup between Shields and Hernandez featured the top two strikeout pitchers in the American League. Both entered with 81 on the season, but Hernandez was clearly the better arm.

"It's been a while since I've got that many runs in one game," Hernandez said. "It felt good. You've got to not relax but (still) make pitches. It was good."

Hernandez had five strikeouts through three innings and escaped a first-inning jam after Matt Joyce doubled but was left at third base. He didn't give up another hit until Sam Fuld's single leading off the fifth and after Johnny Damon's two-out walk in the first, retired 10 of the next 11. Hernandez lost his shutout in the sixth when Evan Longoria and Damon hit consecutive singles and Felipe Lopez scored Longoria with a two-out hit.

Hernandez left after throwing just 97 pitches, given a break after throwing a career high-tying 128 pitches in his last start against the New York Yankees.

"We knocked him out of the game after seven innings and 11 strikeouts," Rays' catcher Kelly Shoppach deadpanned.

Game notes
Seattle optioned OF Michael Saunders to Triple-A Tacoma after Thursday's game and recalled OF Greg Halman. ... Seattle's last four homer game came on Sept. 22, 2010, at Toronto when Jose Lopez hit three in the game. ... Tampa Bay RHP Jeremy Hellickson was honored as the AL rookie of the month and AL pitcher of the month for May on Thursday. He's the first rookie to double up on the award since Dontrelle Willis with Florida in 2003. ... The Mariners improved to 7-0 against Tampa Bay at home in games that Hernandez starts. In his previous six starts against the Rays at home, Hernandez received just nine total runs of support.