SEATTLE -- Two years ago, the A's came close to signing Hisashi Iwakuma out of Japan, but the deal fell apart.
That was an opportunity squandered for Oakland, because Iwakuma is looking more and more like the real deal. Pitching for Seattle, he dominated the A's for seven innings Friday in leading the Mariners to a 6-3 win that left the A's with their fifth consecutive loss.
More than that, Seattle, which has been the only American League West team to give the A's trouble this season, knocked Oakland under .500 for the first time since the first week of the season when the A's started with back-to-back losses to Seattle.
Iwakuma, 13-7 in less than a full season in the Mariners' rotation, gave up a leadoff single to his former catcher in Seattle, John Jaso, then retired the next 16 batters in succession while the Mariners built a 6-0 lead against A's starter Dan Straily.
Not all of that was Straily's doing. A botched double-play grounder on which third baseman Josh Donaldson cut in front of shortstop Jed Lowrie led to two first-inning runs. The three runs in the third were all Straily's, however, as he was touched for a three-run, two-out homer by Raul Ibanez after allowing a single and a walk.
The Mariners added one more run off Straily on Kendrys Morales' fifth-inning RBI double before the A's did anything with Iwakuma.
Straily, who is on the roster as a fill-in for the disabled Brett Anderson, may be asked to make one more start before Anderson comes off the disabled list, assuming all goes well, next Friday. But manager Bob Melvin may look for alternatives, because in the three starts Straily has made with Anderson out, he has allowed 15 runs in 15 innings, although Friday's game was his first loss.
Iwakuma, who entered the game with the best ERA at home of any pitcher in the major leagues at 0.48, finally gave up a sixth-inning infield single to Eric Sogard and another hit to Jaso before Lowrie's two-run double got Oakland on the scoreboard.
Iwakuma also had the best ERA of any American League starting pitcher since the All-Star break at 2.21 entering Friday.
Yoenis Cespedes was the only A's batter to come into the game with more than one career hit off Iwakuma. But Cespedes went 0 for 3 with two strikeouts against Iwakuma.