SEATTLE (AP) -- Seattle manager Eric Wedge knew he was short in the bullpen Monday night.
Prior to the game, he was aware former closer Brandon League was being traded to the Los Angeles Dodgers. Current closer Tom Wilhelmsen had left Safeco Field to be with his pregnant wife. About midway through the game, Wedge learned hard-throwing Steve Delabar was not at his disposal either, because he was being traded down the hall to the Blue Jays in another deal.
Mariners' starter Hisashi Iwakuma didn't know it, but a dominant outing was precisely what his club needed with a thin bullpen.
Iwakuma struck out a career-high 13 and Michael Saunders and Kyle Seager had two hits apiece to help Seattle win its fifth consecutive game 4-1 over the Toronto Blue Jays.
''He was fantastic tonight,'' Wedge said. ''We really needed him to step up. We were obviously very short in the bullpen tonight. For him to go eight strong innings against a very good hitting ballclub, just a great performance.''
Adding to the Iwakuma's strain was the fact he just returned from a trip to Japan on Saturday for personal reasons. Wedge opted not to inform Iwakuma of how short the bullpen was.
''I don't think we needed to add pressure to that,'' Wedge said. ''We tried to keep that close to the vest.''
Iwakuma (2-2) struck out Rajai Davis three straight times after allowing Davis' first career leadoff homer, which gave the Blue Jays a brief 1-0 lead.
Iwakuma's 13 strikeouts broke the Mariners rookie record of 12 previously shared by Mark Langston, Randy Johnson and Freddy Garcia. Iwakuma threw eight innings, allowed four hits and walked three.
Toronto starter Ricky Romero (8-8) went six innings, allowed eight hits and three earned runs. He struck out seven and walked two. Romero has lost seven consecutive starts.
''I think overall, there was much more conviction and trust and belief in his stuff,'' Toronto manager John Farrell said. ''Evident by the first-pitch strikes; he used his fastball much more aggressively. Still not to the point where we've seen Ricky pitch many times before, but I think this is a step in the right direction.''
The Blue Jays removed left fielder Travis Snider after the sixth inning because they traded him to Pittsburgh for right-handed starter Brad Lincoln.
The Mariners tacked on a run in the third thanks to a wild pitch, a passed ball and an error by third baseman Brett Lawrie on Brendan Ryan's grounder that scored Mike Carp, who singled.
Michael Saunders added an RBI double in the fifth.
Iwakuma teetered on occasion after the first, but still held down the Blue Jays. Seager charged Jeff Mathis' grounder and threw out Yunel Escobar at the plate in the second. Colby Rasmus drove Saunders to the center-field wall in fifth inning, but Saunders made the catch on the warning track.
Iwakuma struck out at least one in each inning he pitched. Lawrie struck out four times and snapped his bat over his knee in the dugout following one at-bat.
The Mariners loaded the bases in the first inning after Jesus Montero's line drive hit second base umpire Tony Randazzo. He jumped and spun to avoid the liner, but it struck him in the left side.
Dustin Ackley came home on the play but had to return to third because the ball hit the umpire and stayed in the infield. John Jaso grounded into a double play to score Ackley. Seager extended his majors-leading two-out RBI total with a single to left to bring in Saunders and put Seattle in front 2-1.
Davis' leadoff homer delighted the large number of Blue Jays fans in Safeco Field. The fans opened the game by singing along to, ''O, Canada'' and dispatched a rousing cheer following Davis' sixth homer of the year.
NOTES: Jose Bautista took swings and hit off the tee with both a fungo and regular bat Monday. Manager John Farrell said Bautista's intensity level was 70-75 percent during his swings. Bautista has been on the 15-day disabled list since July 17 because of left wrist inflammation. . Blue Jays RHP Brandon Morrow came out of Sunday's rehabilitation start in good shape. He hit 95 mph on the radar gun and threw 26 pitches in three innings. Toronto plans to give Morrow three more minor league starts. Morrow went on the 60-day disabled list June 13 because of a strained left oblique. . The Blue Jays placed 1B/DH Adam Lind on the 15-day disabled list Monday, retroactive to July 26, with a mid-back strain.