For the vast majority of this latest home game adventure, the Mariners seemed headed toward a predictable conclusion.

They'd fielded a makeshift lineup for injury and merit reasons, then couldn't buy a hit when it mattered after the visiting Baltimore Orioles had capitalized big on the precious few they managed. But the tide finally turned into what became a 6-3 victory on Monday night when Casper Wells did what few Mariners hitters had managed before him throughout this homestand.

Wells came through with a bases-clearing, two-out double in the seventh inning, which turned a deficit into a lead for a Mariners team that finally found the ignition switch to a multiple-run rally.

"It's huge, coming off such tight games with the Red Sox," Wells said. "To be able to pull out ... it was a good all-around team effort."

The all-around part came from a pitching staff that held the Orioles to just three hits. Hisashi Iwakuma gave up all of them in a five-inning, long-awaited major league debut as a starter.

Steve Delabar, Shawn Kelley and Tom Wilhelmsen kicked in four hitless innings of relief. Delabar picked up the victory by tossing two scoreless innings while Wilhelmsen added the save by pitching his third straight day as rumors surfaced that the Mariners might attempt to deal him by the July 31 trade deadline.

But for the longest time, it seemed like one of the hits allowed by Iwakuma — a three-run homer crushed to right field by Chris Davis in the fourth inning for a 3-1 lead — would be enough for the victory.

A crowd of 14,805 at Safeco Field had seen the Mariners squander a sixth-inning chance with runners at second and third and one out, then saw Brendan Ryan pop out foul to the catcher with runners at the corners and one out in the seventh. But Ichiro drew a two-out walk off Orioles starter Jason Hammel to load the bases and bring up Wells, who took a first-pitch strike before lining a slider to the right-center gap.

"I saw quite a bunch of those," Wells said of Hammel's slider. "He's got a pretty good one. He left it up. I knew he was going to be around the strike zone. There was nowhere else to go. The bases were pretty jam-packed there."

Wells helped open the offensive floodgates after his double gave Seattle a 4-3 lead. In the eighth, Miguel Olivo and Dustin Ackley delivered back-to-back home runs off Orioles reliever Troy Patton to provide Wilhelmsen some needed insurance.

It was Ackley's first home run in more than a month and his first long ball at Safeco Field in nearly a year, dating to last July 30.

Wells had been 2 for 19 on the homestand before rallying with hits his final two at-bats. But he'd delivered a big hit Thursday night in a win over Boston, as well as some others before the homestand.

"There's no room to be thinking abut yourself or anything when you're up at the plate," Wells said. "You've got to focus on the pitcher and have your energy sent out towards him so you can try to battle him. That's all you're going to be doing out there."

And the Mariners did battle on a night they saw struggling first baseman Justin Smoak and catcher Jesus Montero on the bench. The makeshift lineup included Ackley at first base and Munenori Kawasaki at second — the latter move allowing the Mariners to start three Japanese players on the field in a game for the first time in major league history.

Kawasaki, Ichiro and Iwakuma all played their part. Ichiro drew the walk to load the bases, while Kawasaki positioned the game's first run by bunting on his own to move Ackley into position to score on Brendan Ryan's single in the third.

Kawasaki also had a single ahead of the Wells double in the seventh. Iwakuma said, through interpreter Daisuke Sekeiba, that the presence of his countrymen on the field helped inspire him.

"I really felt energized to pitch because of the two other guys out there together," he said.

Iwakuma's pitches appeared to have good movement, especially early. He said he can notice a difference between how he's pitching now compared to in spring training, when the team relegated him to bullpen duty.

"My fastball is better than in spring training," he said. "And my breaking balls move better, I think, so it feels much better to pitch."

Mariners manager Eric Wedge said he was pleased that Iwakuma gave the team a chance to win. And that, when given that chance, his players finally took advantage with their bats.

"When you get a starter late in the ballgame there, you're hoping that maybe you get a mistake or a pitch to hit and we got a couple of those," Wedge said. "But the fact of the matter is, you've still have to hit them. And that's been our biggest issue."

Geoff Baker: 206-464-8286 or gbaker@seattletimes.com. On Twitter @gbakermariners. Read his daily blog at www.seattletimes.com/Mariners.