The Red Sox could not solve James Paxton, leaving Boston with a four-game split against the Seattle Mariners.
Paxton stretched his scoreless streak to a career-best 20 innings in a 5-0 win Sunday as Boston finished a 5-5 trip.
"We had some good at-bats," Dustin Pedroia said. "We hit the ball hard. We just didn't get hits or didn't put it all together."
Paxton (2-2) allowed five hits in eight innings, struck out two and walked two, and Carson Smith pitched a perfect ninth.
Steven Wright (1-1), staring in place of an injured Justin Masterson, gave up just three runs - two earned - and five hits in five innings.
Boston put runners in scoring position just twice. Brad Miller snagged a hard hit groundball at shortstop from Pedroia to strand Blake Swihart at third base in the third inning. Swihart hit an inning-ending grounder with runners at second and third in the seventh inning as Paxton worked out of a jam.
"He threw a lot of strikes, came right after us with the good fastball," Red Sox manager John Farrell said. "We had a couple opportunities but the two-out hit wasn't there."
Boston batted .201 on the trip and scored 23 runs.
"We're not hitting right now," Hanley Ramirez said. "We've got to start hitting."
Consecutive singles from Seager and Logan Morrison put runners on the corners with no outs in the second inning. Seager scored from third on a passed ball off Swihart's mask that went to the backstop, and Mike Zunino hit a two-out RBI single beyond the outstretched glove of Pedroia at shortstop.
Miller homered just inside the right field foul pole in the fifth for a 3-0 lead, his fourth home run in five games and third in the last two days.
"It stayed up a little bit more than I wanted it to," Wright said. "... He's just a good hitter, kept his hands back and was able to wrap it around the pole."
Wright needed to make the start after Masterson landed on the disabled list with right shoulder tendonitis on Thursday. Farrell felt Wright did enough to keep them in the ball game.
"I thought he threw a number of good knuckleballs," Farrell said. "Miller, who the last couple of days has kind of caught fire, gets a knuckleball up in the strike zone for a home run, but five innings, three runs keeps the game in check and it didn't get away from him."
After Nelson Cruz walked in the eighth, Seager homered on the first pitch from Craig Breslow.
Pedroia extended his on-base streak to 22 consecutive games, the fifth-longest streak of his career, with a walk in the first inning. Pedroia is hitting .280 with seven runs scored, two doubles, a home run, six RBIs and 14 walks over that span.
Red Sox: Masterson threw on flat ground before Sunday's game. Farrell said the inflammation in Masterson's right shoulder has lessened and he hopes to get Masterson back on the mound by midweek for some bullpen sessions before a rehab assignment.
Mariners: CF Austin Jackson went 2 for 4 for Triple-A Tacoma as he began a rehab stint Saturday night. Jackson has been on the disabled list since May 4 with a right ankle sprain. Jackson is expected to play the field for Tacoma for the first time on Sunday.
LHP Wade Miley (2-4, 5.60 ERA) will make his second-career start against the Texas Rangers on Tuesday. Miley lost his only decision against Texas despite allowing one run and three hits in 7 2/3 innings while with Arizona on June 13, 2012.