The Orioles know what they are going to get when they face Toronto Blue Jays left-hander Ricky Romero, one of the toughest young pitchers in the American League.

With his nasty changeup, low-to-mid-90s fastball and a good curve, Romero has pitched very well at times against the Orioles in his previous two seasons in the majors.

His performance Wednesday night in a 4-1 Toronto victory, however, was about as dominant as a pitcher has been against the Orioles this season.

Romero set a season high and tied a career best with 12 strikeouts while allowing just three hits and two walks through eight scoreless innings before tiring and walking his final two batters to start the ninth.

"He dealt. He had that changeup, and every count he threw it," said center fielder Adam Jones, who was 0-for-3 with a walk and strikeout. "He had me off balance; he had a lot of people off balance."

On June 4 in Baltimore, Romero had been hammered for five runs and 11 hits. It's probably safe to call that one the exception.

"He pitched us differently tonight, too," Orioles manager Buck Showalter said. "He made some adjustments to some of the things we did, and, of course, with him carrying those three pitches, it's a tough proposition for anybody."

The Orioles (30-35) have dropped 16 straight at Rogers Centre, a Toronto franchise record that dates to the Orioles' last win here Aug. 7, 2009. It was also the Orioles' fourth consecutive loss overall while the Blue Jays (34-34) have climbed back to .500.

Give credit to Romero (6-6) -- and to the Jays' big-swing offense that bashed three homers -- for this latest humbling.

Romero fell short of a complete-game shutout when he was pulled in the ninth after walking Nick Markakis and Jones. Frank Francisco entered and picked up his sixth save but allowed Matt Wieters' RBI single -- with the run charged to Romero -- before getting Derrek Lee to end the game on a double play.

"I felt like I had a good curveball going, a good changeup going and I could locate my fastball wherever I wanted," said Romero, whose ERA dropped to 3.01 while he improved to 4-3 with a 3.57 ERA in 10 career starts against the Orioles. "Those are the nights you have to take advantage of as a starter. You can't take it for granted because these days don't come very often. When you're feeling good, you definitely have to take full advantage of it."

At least Romero spread the agony around, striking out more Orioles than any other pitcher in a game this season. Every Oriole in the starting lineup with the exception of Markakis and Vladimir Guerrero struck out Wednesday. Nolan Reimold fanned in all three of his at-bats.

"He was pretty good," Reimold said. "His changeup was working a lot. He was throwing a lot of them and getting guys to swing, chasing them a lot. … It was a tough day."

After Romero retired the first nine batters he faced on a total of 30 pitches, the Orioles finally put together a mini rally.

J.J. Hardy led off the fourth with a double to left, and Markakis followed with a walk, setting up runners on first and second and no outs.

Jones saw six pitches but flailed at a changeup in the dirt. Guerrero bounced the next pitch to shortstop Yunel Escobar for a 6-4-3, inning-ending double play.

That was the extent of the Orioles' threats, wiping out a good outing by Jake Arrieta (8-4). He allowed two solo homers through the first six innings. In the seventh, he issued a two-out walk to Jose Bautista and was pulled after throwing 102 pitches (65 for strikes).

"I think it was pretty good overall," said Arrieta, who had won two straight decisions. "I attacked the hitters for the most part really well. The consequence was a few knocks, a few base hits and the home runs were the big blows there. But they were solo shots. … That's a good ballclub, they hit a lot of home runs, and they found a way to get a couple off me tonight."

Lefty Clay Rapada entered to face left-handed slugger Adam Lind, who hit Rapada's fifth pitch over the right-field wall for his 13th homer of the season. Lind was the only batter Rapada faced.