BOSTON (AP) -- Justin Masterson is making it difficult for the Red Sox to send him back to the minors.
"Every time he takes the ball, the organization's got their chest out a little, as they should," Red Sox manager Terry Francona said. "This isn't a fluke. He's been prepared very well how to pitch, how to act and how to compete. It's exciting."
Masterson (3-0) gave up one run on three hits and struck out four for Boston, which has won 15 of its last 16 at home and eight of 10 overall. Jonathan Papelbon pitched a perfect ninth for his 18th save.
"Anytime you get called up, you want to do your best," Masterson said. "I am just trying to give us a chance to win."
"A lot of his success is bred from confidence he has gained from his starts," catcher Jason Varitek said.
Drew greeted Seattle reliever Sean Green (1-2) with his eighth homer of the season in the sixth inning to break a 1-1 tie. It was only the second homer allowed by Green, who made his 32nd appearance, tied for first in the American League.
"He's been hot and he got me," Green said. "I have no explanation for our road woes. We're playing hard and it's just not happening right now."
Seattle has dropped 15 of 17 on the road.
Mariners starter Erik Bedard lasted only five innings, despite giving up only two hits and one run. It was only the third time in his last six starts that he has made it through the fifth.
Seattle went ahead 1-0 in the second inning on an RBI groundout by Yuniesky Betancourt. On the previous at-bat by Richie Sexson, Drew made a highlight-reel over-the-shoulder catch while battling the sun to rob Sexson of extra bases.
"Sexson hit that ball well, but Drew ran it down," Mariners manager John McLaren said. "Bedard hung in there well, but he threw a lot of pitches."
Boston tied it in the third at 1, but failed to break it open when Bedard struggled with his control while throwing 40 pitches. After Coco Crisp singled, Brandon Moss and Dustin Pedroia walked to load the bases. Drew was hit by a pitch forcing Crisp home, but Manny Ramirez struck out to end the threat. Ramirez later extended his hitting streak to 13 games.
Masterson became the first pitcher in the history of Fenway Park to go unbeaten in his first four starts. Francona announced before the game that he hoped Jacoby Ellsbury would return to the Boston lineup Tuesday. ... Bedard has allowed one run in 12 innings against Boston this season.