CLEVELAND -- Hisashi Iwakuma kept his road record spotless with one minor blemish.
Iwakuma (9-5) improved to 9-0 with a 2.17 ERA in his last 14 road starts, the second-longest such streak in club history. The Japanese right-hander is 5-0 outside Seattle this season.
"I didn't even know that," Iwakuma, speaking through a translator, said of his road perfection. "I don't what the secret is."
Dustin Ackley hit a two-run double in Seattle's four-run fourth against Trevor Bauer (4-6). Mike Zunino homered in the fifth for the Mariners, one of six teams scrapping for the AL's second wild-card spot.
The Indians are 5-7 since the All-Star break and are trying to decide whether to be active before Thursday's trade deadline.
Once again, Iwakuma didn't do anything to hurt himself. He allowed two runs and six hits, and only walked one -- his first free pass in six starts. The right-hander has walked just nine all season.
"I'm a little disappointed he walked a batter," joked Seattle manager Lloyd McClendon. "He's pretty good. He did a nice job for us."
Iwakuma went 35 2/3 innings and 139 consecutive batters without giving up a walk before he put Michael Brantley on with four consecutive balls in the first.
McClendon laughed about Iwakuma's stunning loss of control.
"He doesn't mess around," McClendon cracked. "He gets it done and gets it out of the way."
Fernando Rodney pitched the ninth for his league-leading 29th save, and 18th in 19 tries.
The Mariners, who came in with the fewest runs scored in the AL, took a 4-0 lead in the fourth when they hit three doubles off Bauer.
Kyle Seager opened the inning by bunting against the shift, pushing a ball down the third-base line. Bauer hit Zunino, and one out later, Corey Hart hit an RBI double. With two outs, Ackley ripped his double off the right-field wall to make it 3-0.
Zunino's 16th homer gave the Mariners a 5-0 lead in the fifth and chased Bauer, who had gone at least six innings in each of his previous four starts.
The Mariners, who hadn't scored five runs in their past six games, improved to 39-10 when scoring four or more in a game.
"That's a good position for us," Ackley said. "When we get ahead, it gives us a better feeling and puts the pressure on them."
Seattle snapped a six-game losing streak in Cleveland. The Mariners' last win at Progressive Field was on Sept. 19, 2011.
Mariners: Left-hander James Paxton (strained back muscle) will throw a bullpen session Wednesday, and as long as there are no setbacks, he could start Saturday in Baltimore. He hasn't pitched in the majors since April 8.
Indians: As center fielder Michael Bourn rehabs his surgically repaired left hamstring, manager Terry Francona is trying to let the speedster recover at his own pace. Bourn has been on the disabled list since July 6, and it's not yet known when he will go on a rehab assignment or be activated. Bourn took batting practice before Tuesday's game.
Two of the AL's top pitchers match up in the second game of the series when Seattle's Felix Hernandez takes on Cleveland's Corey Kluber. Hernandez (11-2) has allowed two runs or less and pitched at least seven innings in 13 consecutive starts, an AL record. King Felix, though, is just 7-5 in his career against the Indians, with all five losses coming in Cleveland.
Kluber (10-6) carried a perfect game into the seventh inning of his previous start.