Jack Cust and Justin Smoak each had solo jobs, but down at the very bottom of the order, rookie left fielder Carlos Peguero tagged Shields for a pair of homers, the second of which ended the starter's shortest stint of the season.
After a mammoth three-run homer to center field in the second inning, Peguero again went straight-away in the fourth with a solo shot. In just 20 games, Peguero has four homers and Thursday's four RBI gave him 12 for the year.
Peguero, a rookie who played last season in the Southern League, is batting just .190 and still feeling his way around American League pitchers, though he's getting steady playing time as the Mariners are not rich in outfielders. Seattle remained 1 1/2 games behind the Texas Rangers in the A West, but increased their advantage over the third place Angels to one game. The win was the first of an important four-game series with the Rays in Seattle.
In taking the fourth and final game of their series in St. Louis by a 12-7 score, the Giants took three of four from the NL Central-leading Cardinals and took back first place in the NL West with a 1/2 game lead over Arizona.
Much-maligned Aubrey Huff, who got off to a poor start, partially due to having to begin the season unaccustomed in right field, blasted three homers for the Giants, driving in six runs to lead the rout.
The trio of long balls were Huff's 6th, 7th and 8th home runs of the season, but, more importantly, helped produce a win in the first series on the road for the Giants since Posey was lost for the season following a collision at home plate on May 25.