Blackburn lasted just 3 2/3 innings, giving up five runs on 10 hits while throwing 80 pitches. It was the right-hander's shortest start of the season.
"It happens every once in a while," Twins manager Ron Gardenhire said. "Our pitching staff has been doing a good job. Blackie has been as good as any of them."
Of the Twins five starting pitchers, Blackburn had entered this start as seemingly his club's go-to pitcher. He had gone 5-0 with a 2.65 ERA in five May starts and entering Tuesday night, the Twins had lost just one of the last 13 contests dating back to Sept. 19 when Blackburn was on the mound.
But on this night, Blackburn couldn't get his sinker working effectively and after minimizing the damage over his first three innings, he saw trouble strike in the fourth.
With the game knotted at 1, Mike Sweeney led off the inning with an infield single to shortstop J.J. Hardy. And the game quickly shifted momentum when Jose Lopez belted a 3-2 fastball from Blackburn that was left up in the zone into the left-field stands for his third homer of the season.
From there, the inning began to unravel for Blackburn, as he gave up a total of six hits in what became a four-inning frame for Seattle. With two outs, Ichiro Suzuki added an RBI single and Chone Figgins followed with an RBI double to give Seattle a 5-1 lead.
"Everything was just a little flat today," Blackburn said. "I think my mechanics were a little out of line and it was one of those things where I couldn't make the adjustment no matter how hard I tried. Obviously, you're going to have days like that and hopefully that's the end of it."
The rough night for Blackburn certainly wasn't helped by the fact that offensively, the Twins couldn't get much going against Mariners starter Jason Vargas, who held them to one run on six hits over seven innings.
The lone run by Minnesota came in the third inning when Justin Morneau crushed a 3-0 pitch from Vargas to right field for his 12th home run of the season.
Vargas, 27, doesn't exactly possess overpowering stuff. Like Mariners right-hander Doug Fister, whom the Twins defeated on Monday night, Vargas reminded Minnesota of some of its own pitchers -- a guy who works more off command and using the entire strike zone than relying on overpowering stuff.
And so far this season, he's used his mid-80s fastball and ability to keep hitters off balance to deliver successful outings for Seattle. Following his start against the Twins, Vargas is now 4-2 with a 2.92 ERA in 10 starts this season.
"Vargas was unbelievable for me, especially with the way that game started --  pitches through three," Mariners manager Don Wakamatsu said. "The fifth inning was critical, the line drive he catches and then rolls the double play and keeps his pitch count in check at that point, and it allowed him to go two more innings. But he was just phenomenal. He left one pitch up on a 3-0 count to an awfully good hitter and that was about the damage of it."
The Twins looked to have earlier opportunities against Vargas. Hardy drew a one-out walk in the first inning and Joe Mauer followed with a double into the right-field corner. But Vargas found his way out of trouble when Morneau lined out to first baseman Casey Kotchman and Michael Cuddyer grounded out.
And in the second inning, the Twins had runners on first and second with two outs, but they couldn't manage to push across a run in that inning either. Overall, they went 0-for-4 with runners in scoring position and left a total of seven men on base.
"There's two different types of pitching," Gardenhire said. "You've got guys who can blow people away with above-average stuff, and you've got guys who know how to pitch. Vargas is one of those guys who knows how to pitch. Knows how to add and subtract. We hit some balls hard, but he never gave into us, either."
After Alex Burnett managed to keep the game within reach over his 2 1/3 scoreless innings, the Mariners extended their lead in the seventh by adding two runs off left-hander Ron Mahay. It was Mahay's first appearance since May 22.
But while the Twins would like to just put this contest behind them, the task becomes even tougher over the final two games of the series. That's because they'll be facing the Mariner's 1-2 punch of Cliff Lee and Felix Hernandez -- two pitchers considered to be among the best in the American League.
Still, the Twins know not to overlook them, as the offense will certainly continue to face a challenge during these next two games in Seattle.
"As I said before we started this trip, there's good pitching on this road trip that we're going to face," Gardenhire said. "And that's what we're seeing up to this point."