ATLANTA -- Lloyd McClendon's unusual lineup left the Seattle manager answering questions about his team's scoring potential.
As it turned out, Hisashi Iwakuma and the Mariners' stingy bullpen didn't need much offense.
Iwakuma combined with two relievers on a six-hit shutout and the streaking Mariners beat the Atlanta Braves 2-0 on Wednesday to complete a two-game sweep.
Cole Gillespie and Kyle Seager hit run-scoring singles. Seattle has won five straight, matching its longest winning streak of the season.
Perhaps the most puzzling piece of the lineup was Stefen Romero, who hit cleanup for the first time this season.
"Somebody has got to hit there," McClendon said before the game. "I don't have Bonds, so it's going to be Romero."
Romero, who hit a pinch-hit homer in Tuesday night's 7-5 win over the Braves, took a .204 batting average into the game. He came through with two hits, including a triple, and scored a run.
Willie Bloomquist had a single and a walk as he started at first base for the first time in four years and hit leadoff for only the second time this year.
Iwakuma overcame an early start -- 9:10 a.m. in Seattle -- and Atlanta's heat to dominate the Braves. The first-pitch temperature was 84 degrees.
Iwakuma (4-2) gave up only six hits with seven strikeouts and no walks in seven innings. The right-hander was sharp, throwing 71 of his 96 pitches for strikes.
"I knew I needed to focus more than regular games because of the heat," Iwakuma said through a translator. "I was just trying to focus and get quick outs to go deeper in the game and that's what I was able to do."
Mike Minor (2-4) allowed only one run in seven innings, but the Braves fell to 0-6 in interleague games.
Yoervis Medina pitched a perfect eighth before Fernando Rodney earned his 16th save with three straight outs in the ninth. Seattle relievers threw eight scoreless innings in the two-game sweep.
The Braves were held scoreless in the final seven innings of Tuesday night's loss. The streak of consecutive scoreless innings reached 16 on Wednesday.
"We had a tough time figuring out their starter," Braves manager Fredi Gonzalez said. "The guy's only throwing 87, 88 miles an hour but he sure looked like he was throwing a lot harder. I know he had movement and some deception but we didn't square up too many balls against him. He was pretty darn good."
Iwakuma, a 2013 All-Star, gave up a combined nine runs in back-to-back losses to Houston and Detroit before returning to form against the Braves.
"He was much better getting the ball down in the zone," Seattle catcher Mike Zunino said. "We wanted to make an emphasis on keeping the ball down and he was. He was able to get to that bottom shelf and stay there for the majority of the game and just mix all his pitches."
Gillespie's RBI single in the fourth gave Seattle a 1-0 lead that held until the eighth, when Romero tripled off Luis Avilan. Pinch-runner James Jones scored on Seager's single to right field.
Minor allowed only five hits and one run in seven innings. He matched his season high with 10 strikeouts.
Freddie Freeman had three strikeouts against Iwakuma and finished 0-for-4.
Gonzalez unsuccessfully challenged first-base umpire Will Little's ninth-inning call that Justin Upton was out at first base on the throw from shortstop Brad Miller. The review lasted only 40 seconds.
Seattle also won five straight from May 3-7. ... Bloomquist's last start at first base came in 2010 with Kansas City. The versatile Bloomquist also has started at second base, third base, shortstop, left field and right field this season, and he is the emergency catcher. ... Seattle players wore T-shirts honoring athletic trainer Rick Griffin's 5,000th regular-season game. He joined the team in 1983. ... The Braves and Mariners are off on Thursday. The Braves open a weekend series at Arizona on Friday, when RHP Julio Teheran faces RHP Brandon McCarthy. Seattle's east coast swing shifts to Tampa Bay, when Mariners RHP Chris Young will face LHP Erik Bedard.