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

Peguero hit a three-run homer as part of Seattle's five-run second inning, then added a solo homer in the fourth. 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.

With eight runs, 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.

How many more chances Peguero gets in left field remains a question. The rookie was hitting only .169 entering Thursday night, but manager Eric 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. Cust's homer earlier in the inning was his second of the season and his first at Safeco Field.

Smoak's homer was his third of the Mariners' 10-game homestand. Seattle has now won 12 of 15.

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.

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. Aaron Laffey took over on relief and gave up an eighth inning homer to Joyce, his 10th of the season.

For Shields, it was his worst start since giving up four homers against Toronto last August. In that loss to the Blue Jays, Shields lasted just four inning as well. Shields also struck out only four, his fewest since April 14 against Minnesota.