SEATTLE -- One of the signs of a veteran pitcher is the ability to win a game without having his best stuff.

Two games into his major league career, Arizona Diamondbacks rookie Zack Godley is already there.

Godley overcame some command issues to pitch six strong innings, and the Diamondbacks provided more than enough offense in an 8-4 win over the Seattle Mariners on Tuesday night. Arizona earned its fifth win in six games.

The Diamondbacks' David Peralta, Chris Owings, Ender Inciarte and Nick Ahmed each drove in a pair of runs, and Godley overcame two mammoth homers to earn his second win in as many starts.

"He's learning that if he keeps the ball down, he'll get a lot of ground balls," manager Chip Hale said of the rookie starter.

Godley (2-0) allowed three runs on seven hits and three walks, giving up home runs to Seattle designated hitter Nelson Cruz (440 feet) and catcher Mike Zunino (452 feet) along the way. Zunino's solo shot in the third inning was the first run scored on Godley in his young career.

"It's going to happen," Godley said with a shrug. "It happens."

Left fielder Peralta went 3-for-4 while driving in runs in the first and third innings, and he added a stolen base in the seventh. Second baseman Owings hit a two-run single in the sixth to break open the game while giving Arizona (48-51) a 6-1 lead. Inciarte, the Diamondbacks' right fielder, went 2-for-5 with a solo home run in the fifth and an RBI single in the eighth.

"We executed well," Peralta said. "We did a little bit of everything today."

Seattle starter Hisashi Iwakuma, the subject of trade rumors because he will be a free agent at season's end, struggled through his worst outing of the year. Iwakuma (2-2) allowed season highs of 10 hits and six runs over 5 2/3 innings.

"Not very good command today," Seattle manager Lloyd McClendon said. "Right from the start."

Mariners shortstop Brad Miller drove in a pair of runs in the loss.

With the loss, the Mariners (46-55) are guaranteed to finish no better than .500 on the current six-game homestand. It marks the fourth consecutive homestand in which Seattle failed to win more games than it lost.

"It's tough, but nobody feels sorry for you in this game," McClendon said. "We've got to continue to grind it out, to continue to get better. We'll come out (Wednesday) and try to win a ballgame."

A fifth-inning solo home run from Inciarte and two RBIs from Peralta put the Diamondbacks ahead 3-1.

Peralta drove in each of the Diamondbacks' first two runs, in the first and third innings, on the way to a 2-0 lead. Seattle finally got on the board with a leadoff home run from Zunino in the bottom of the third.

Arizona center fielder A.J. Pollock stole his 23rd base of the season in the top of the first inning, setting up the Diamondbacks' first run of the game. Peralta drove in Pollock with an RBI single.

Peralta added another RBI on a third-inning double, which scored first baseman Paul Goldschmidt from first but also resulted in the third out of the frame when Peralta was caught in a rundown between second and third base.

NOTES: After the game, Arizona placed RHP Randall Delgado on the 15-day disabled list due to a sprained ankle he sustained during warmups. The Diamondbacks recalled RHP Addison Reed from Triple-A Reno to replace him. ... Diamondbacks C Welington Castillo (bruised elbow) did not play. He took a pitch off his left elbow twice in a span of three games, but there doesn't appear to be any structural damage. ... The Mariners' roller-coaster July has resulted in an 11-13 record. Seattle has one two-game winning streak during that span and three two-game losing streaks. ... Mariners LF Dustin Ackley got a rare start Tuesday, his first of the homestand and only his fourth since July 10. He went 1-for-4. Struggling 1B Logan Morrison was on the bench for the second time in three games. ... Arizona RHP Brad Ziegler was one of 15 players nominated for the Bob Feller Act of Valor Award. The honor is given to the major league player who annually best exemplifies Feller's integrity, values and dedication.