SEATTLE -- The strut that Taijuan Walker carried through an impressive April had been replaced by looks of bewilderment and disgust over his past few outings, and the 23-year-old Seattle Mariners starting pitcher wasn't about to let his team down again.

Walker finally found his form again and turned in one of his best outings of the season in beating the Cleveland Indians 5-0 on Wednesday night.

"It's just (about) being more intense and having that edge, going after them with my fastball and keeping it up the whole game," he said after throwing eight scoreless innings and allowing just three hits to earn his first win since April 25.

Walker (3-6) matched his career high with 11 strikeouts and did not issue a walk.

"I'm not sure what he's doing to other teams, but he's been good against us," Cleveland manager Terry Francona said. "That was a dominating performance."

Catcher Chris Iannetta hit two home runs and drove in Seattle's first four runs on a night when Walker didn't need much offense. Iannetta homered in the third and fifth innings before adding an RBI double in the seventh.

"You always remember doing it," said Iannetta, whose only other multi-home run game came in May 2011. "I had a couple of two-home-run games in the minor leagues but only one in the big leagues. It was fun to do it again.

Walker retired the first nine Cleveland hitters and left the game after getting the final nine he faced through the eighth. He threw 110 pitches, 76 for strikes.

Reliever Nick Vincent finished off the shutout with a scoreless ninth, striking out two to give Cleveland 13 strikeouts for the night.

It marked the first time since May 7 that the Indians (32-26) were held scoreless. Cleveland has just nine hits and one run over the past two games of the series.

Cleveland starter Carlos Carrasco wasn't bad but suffered his first loss of the season after serving up both of Iannetta's homers. Carrasco (2-1) allowed four runs off five hits over 6 2/3 innings, with one walk and six strikeouts.

"Iannetta's a strong kid, and (Carrasco) left some pitches middle to middle," Francona said. "That ended up being way too much the way Walker was pitching."

The only time the Indians had a runner in scoring position came when Cleveland led off the fourth with back-to-back singles. Walker got out of that jam with three consecutive outs, including an inning-ending strikeout that left Indians batter Lonnie Chisenhall slamming both his bat and batting helmet into the dirt.

"(Walker) didn't back down," Seattle manager Scott Servais said. "He just dialed it up."

Walker retired the first nine Cleveland batters in order before Davis led off the fourth with a single, the Indians' first hit of the game.

Iannetta went 3-for-3 with four RBIs in the win, while shortstop Ketel Marte added two singles and two stolen bases. Robinson Cano went 2-for-4 with a double for Seattle (33-26).

Iannetta homered in each of his first two at-bats Wednesday, putting the Mariners ahead with a two-run shot in the third and a solo homer in the fifth.

Iannetta's first homer gave the Mariners a 2-0 lead in the third inning. Marte opened the inning with the first hit of the game, a single to center, then Iannetta hit his fifth home run of the season with a fly ball that cleared the glove of left fielder Rajai Davis by a foot or two and landed in the visiting bullpen.

In the fifth, Iannetta went deep again, hitting a 3-2 pitch from Indians starter Carlos Carrasco into the section above the visiting bullpen for a 3-0 Mariners lead. It was Iannetta's fifth home run of the season.

The Indians welcomed the return of veteran reliever Joba Chamberlain, who came off the disabled list earlier in the day but allowed a double and a run in his only inning of work.

NOTES: Cleveland activated RHP Joba Chamberlain from the 15-day disabled list before Wednesday's game. RHP Cody Anderson, who was called up to start Tuesday, was sent back to Triple-A Columbus. ... Seattle SS Ketel Marte (neck spasms) was back in the lineup Wednesday. ... Indians C Yan Gomes underwent an ultrasound after suffering a testicular contusion in Tuesday's game, and manager Terry Francona said there was no major damage. Gomes was not in the lineup Wednesday, but Francona did not rule out the possibility of him being available if the Indians were to need a backup catcher. ... OF Jose Ramirez was a late scratch for the Indians after his bruised left shin flared up before the game. Ramirez fouled a ball off his lower leg in Tuesday night's loss. ... Despite their hot start that has put them atop the American League Central standings, the Indians don't have a player among the top five vote-getters at any position in the latest All-Star Game voting. No Cleveland player is among the top 15 outfielders. The only two Seattle players on the list are 2B Robinson Cano (third) and DH Nelson Cruz (fifth).