After a first-inning RBI single by Cody Ross, Jason Vargas neutralized the Boston Red Sox over his final six innings of work, helping the Seattle Mariners to a 4-1 victory in the opener of a three- game set.
In all, Vargas (14-9) pitched seven innings, allowing six hits and one run, while striking out five. He became the first pitcher besides Felix Hernandez to win 14 games for the club since 2003.
Tom Wilhelmsen locked it down in the ninth, recording his 23rd save of the season. He worked around a one-out error by Dustin Ackley and retired the final two batters by groundout.
The Red Sox have now lost seven games in a row and 12 of their last 15.
"We just need to be better," Red Sox catcher Ryan Lavarnway said. "We can't feel sorry for ourselves and let the frustration get the better of us. We're a better team than this and better players than this. Trying is not enough right now, we've got to be better."
Overall, Clay Buchholz (11-5) pitched well, but struggled in the fourth inning behind some shaky defense. Buchholz went seven innings and gave up four runs - three earned - on six hits. He struck out eight and walked one.
The Mariners scored all four of their runs in the fourth. After Franklin Gutierrez led off the inning with a single, Buchholz plunked Kyle Seager to put the first two batters on. John Jaso and Justin Smoak followed with consecutive RBI singles to right field, which scored Gutierrez and Seager to give the Mariners a 2-1 lead.
Buchholz then got Eric Thames to fly out to Jacoby Ellsbury, but the center fielder was charged with an error for a poor throw to the plate, which allowed Jaso to score from third. After a Miguel Olivo single, Carlos Peguero reached on a fielding error by shortstop Jose Iglesias, allowing Smoak to score from third, capping the inning.
"We made the miscues that gave them two runs and that's all she wrote," Boston manager Bobby Valentine said.
The Red Sox scored their only run of the game in the first after Dustin Pedroia stroked a two-out, ground-rule double to left-center field. Ross followed and came through with an RBI single to score the game's first run.
Pedroia tallied his 1,000th career hit and extended his hitting streak to 14 games on Monday with two hits against the Mariners ... Buchholz made his 100th career major league start ... The Mariners are 30-18 since the All- Star break ... Jaso has reached base safely in 31 of his 32 starts since All- Star break.