"That's freaking terrible right there," Hernandez said. "If you throw a ball in the middle of the plate, they're going to hit it. It's on me."
Hernandez has gone 0-3 with a 9.00 ERA in September, giving up 16 runs and 30 hits in 16 innings to the Angels, A's and Blue Jays. As a result, his AL-leading ERA of 2.43 at the end of August now sits at 2.92, which is fifth in the league.
This is the first time Hernandez has lost three straight decisions since his final three outings last year. After giving up 11 hits and six runs in 4 2/3 innings to the A's six days earlier, Hernandez said none of his pitches were working.
"I have to do something," he said in a quiet Mariners clubhouse. "The last three starts have been freaking disappointing. So, there's nothing to say."
All five of the fourth-inning runs came after Hernandez had two outs and an 0-2 count on Brett Lawrie.
But Lawrie battled back for a two-run single and Edwin Encarnacion followed with a three-run blast -- his 40th of the season -- on a night Hernandez had already allowed a two-run home run to Adam Lind in the first.
Hernandez, who has thrown a league-high 212 2/3 innings, allowed three home runs in his past two starts after giving up just two long balls in his previous 16 outings.
"I think there were some control issues," said catcher John Jaso, who also worked with Hernandez through most of his nine-game winning streak prior to his current struggles. "The homer to Lind got over the plate a little bit and there were a couple more there. But the Blue Jays were hitting today. They're swinging the bats well. They weren't taking many pitches, and they were hitting mistakes."
Mariners manager Eric Wedge said the Blue Jays did a good job looking for Hernandez's fastball on a night he didn't have his normal command.
"I just felt like he was missing some spots with his fastball," Wedge said. "And they were aggressive with him. He was so close to working through that [fourth] inning, we just couldn't get that final out. It looked like his stuff was pretty good, he just didn't have the same location he normally has."
Jaso said Encarnacion's home run -- his fifth in nine games against Seattle this season -- was not on a mistake, however.
"That was a decent pitch," he said of the 1-2 changeup. "He just hit it a mile. Tip your cap. He did a good job with that, and he's done it 40 times this year."
The Blue Jays were thrilled to get to the 2010 AL Cy Young winner in their first meeting with him this season.
"You don't see that very often against Felix Hernandez," said Encarnacion. "He's one of the best pitchers in the league, but we made good adjustments against him, so we feel very happy, because it's not easy hitting against him."
The loss prevented the Mariners from sweeping the Blue Jays in Toronto for the first time since 2001, but they concluded their season series with a 6-3 advantage.
The Mariners (69-75) now head to Texas to begin a stretch where their final 18 games are against teams with winning records.
Right fielder Carlos Peguero, making his first start since Sept. 3, laced a two-run double in the second inning and Dustin Ackley ripped a solo home run in the seventh for the only damage against Blue Jays rookie Henderson Alvarez, who improved to 9-12.
Hernandez's rough fourth inning came after Blue Jays left fielder Rajai Davis had some bizarre baserunning exploits. The speedy Davis singled on a bunt down the third-base line, with Kyle Seager letting the ball roll so long that Davis took off for second and was momentarily caught in a rundown.
But Davis got back to first when shortstop Brendan Ryan's throw hit him in the back, then stole second. When Jeff Mathis followed with another bunt to third, Seager picked up the ball, realized he couldn't get Mathis at first and wheeled and fired to Ryan at third to catch Davis after he'd rounded the bag too far.
All that wound up eliminating one baserunner and giving Hernandez two outs, but it didn't stop the Blue Jays, as Anthony Gose followed with a double to put runners on second and third, and Lawrie drove both in with his single for a 4-2 lead.
Hernandez's night then got worse in a hurry when he walked Colby Rasmus and surrendered the three-run blast to Encarnacion. But he said there's only one solution now.
"I just have to throw the ball the way I want to throw it and I'll be OK," he said. "We'll move on. Just turn the page."
Wedge went to his bench in the late innings, replacing five position players and giving rookie Carlos Triunfel his first Major League action in the field at shortstop for the final three frames. Triunfel recorded his first hit, a double in the ninth.