SEATTLE (AP) — Omar Narvaez hit a three-run homer off Rick Porcello in Seattle’s seven-run third inning, and the Mariners beat the Boston Red Sox 10-8 on Sunday.

Dee Gordon had two hits and three RBIs as Seattle put together another impressive performance at the plate. The Mariners scored 34 times while taking three of four from the defending World Series champions in their first series at home.

Jay Bruce also connected for Seattle, and Mitch Haniger had two hits and two RBIs. The Mariners have 15 homers so far, hitting at least one in each of their six games.

Porcello (0-1) allowed nine runs, four earned, and six hits in 2 2/3 innings. The 2016 AL Cy Young Award winner struck out three and walked four.

Starters Porcello, Chris Sale, Nathan Eovaldi and Eduardo Rodriguez combined to give up 22 earned runs on 27 hits in the four games against Seattle.

Cory Gearrin came on to pitch the ninth for Seattle and walked the bases loaded with one out. Gearrin was then replaced by Chasen Bradford, who walked pinch hitter Blake Swihart to force in a run before retiring Christian Vazquez and Jackie Bradley Jr. to end the game.

Bradford is the third pitcher to record a save for the Mariners this season.

Narvaez’s drive to right put Seattle ahead to stay. Haniger capped the big inning with a two-run double.

Mariners starter Wade LeBlanc (1-0) allowed six runs, four earned, and seven hits in 5 1/3 innings.

J.D. Martinez hit an RBI single in Boston’s three-run first, and then belted a three-run drive in the fourth for his second homer this season.