TORONTO -- The signs showcasing the potency of the Blue Jays' bats were everywhere.

Toronto entered the three-game series against Baltimore leading the American League in several offensive categories, including homers, runs scored and doubles. Orioles manager Dave Trembley made it a point in his team's pre-series meeting to point out the Blue Jays' ability to pounce. But the message apparently fell largely on deaf ears, as the Orioles helped the free-swinging Jays inflate their power numbers, surrendering four homers Saturday en route to a 5-2 loss in front of a crowd of 16,194 at the Rogers Centre.

"What I said at the beginning of the series was, your first pitch has to be a quality pitch," Trembley said. "They are an ambush-type team. They don't take a whole lot [of pitches]. They don't walk a whole lot. They go up there looking to swing. You make mistakes, they don't foul them straight back. They hit them."

And they hit them far. Toronto scored all five of its runs via the homer -- two of which were launched into the upper deck -- as the Orioles surrendered a multi-homer inning for the second straight game. The loss is Baltimore's fifth straight to Toronto this season and its seventh in a row inside the Jays' home dome. The Orioles (15-35) are now a Major League-worst 20 games below .500 and have scored three runs or fewer in 30 of 50 games.

Top pitching prospect Chris Tillman, who was officially recalled following Friday's game, made his season debut and tossed 5 2/3 innings, yielding only a pair of homers. The 22-year-old Tillman allowed a double to the first batter he faced but responded by striking out the side, ending with a 10-pitch "K" of cleanup batter Vernon Wells, who saw a steady diet of low-90s fastballs.

"His fastball was sneaky at times," Wells said of Tillman. "I think he's another guy that's still kind of learning at this level. He's got good enough stuff to be a really good one, especially in this division."

Tillman surrendered a two-out homer to Lyle Overbay in the second and didn't allow another Toronto run until Aaron Hill went yard to open the sixth. Hill's game-tying homer was a big blow given that the Orioles had just regained the lead by scoring a pair of runs off Toronto's starter Brett Cecil in the top of the frame.

"I was falling off a little bit [on the mound], trying to stay in line," said Tillman, who conferred with pitching coach Rick Kranitz between innings. "I just wanted to get ahead of [Hill] there, and it went right over the plate and he did what he did."

Tillman's belt-high fastball was one of several mistake pitches the Blue Jays sent screaming into the seats, as the Orioles lost their 11th in 14 games and went away from everything Trembley preached.

"You go and get two runs and Tillman goes out there with a 2-1 lead and he throws an 87-miles-an-hour fastball to try and get the first pitch over to a guy who is an All-Star second baseman," Trembley said. "You've got to do better than that.

"[Reliever Jason] Berken does a heck of a job but then gets Vernon [Wells] in a count where perhaps he's going to chase. He showed earlier in the game that if you get ahead of him, he might chase either up or out of the strike zone, and we throw a hanging slider and he hits it in the second deck.

"And [Alberto] Castillo comes in, I think it's the fourth time against a left-handed hitter that he's come into the game and, on the first pitch, he's hung a slider and the guy has hit it in the seats. That's the difference in the game for me."

Berken has been one of the Orioles' most reliable relief options in the wake of injuries to Mike Gonzalez, Jim Johnson, Alfredo Simon and Koji Uehara. But after recording the final out of the sixth and tossing a scoreless seventh, the right-hander hung a 1-2 slider that Wells sent ricocheting off the third deck of the left-field stands.

"Vernon is a good offspeed hitter in the strike zone," Berken said. "I was trying to put it out of the zone and I didn't, and usually when you get a slider up, they go a long way. And that one did."

Wells' eighth-inning blast gave the Jays a lead they would only add to, as Castillo allowed Overbay to notch his second homer, and Toronto's franchise record-setting 50th long ball of the month.

"These guys are swinging the bat well right now," Tillman said of Toronto. "I think that is in the back of your head, but at the same time you got to do what you got to do, you know? I think I stuck with the game plan pretty well today."

But Cecil was better. The tough lefty kept the O's batters in fits, retiring the first 10 he faced before Nick Markakis singled on a sharp ground ball to center field in the fourth inning.

"[Cecil] was throwing on the black, both sides," Garrett Atkins said. "When a pitchers doing that, it doesn't matter how hard they're throwing. They're painting, keeping guys off balance and he did a good job of that through the first five innings."

The Orioles tagged Cecil for a pair of a runs in the sixth, staging a mini-rally that started with Cesar Izturis' two-out double. Julio Lugo singled in Izturis, advanced to second on the throw and scored on Markakis' hit to left field.

For the beleaguered Orioles bats, Izturis' double was the team's first extra-base hit since Garrett Atkins homered on Wednesday, a drought that stretched 107 at-bats.

"I don't have an answer for you," infielder Ty Wigginton said of the Orioles' puzzling lack of power. "I wish I did have an answer, but I don't."

The Orioles didn't have answer for Cecil, either. Following the two-run sixth, he continued to cruise, tossing just seven pitches each in the next two innings. Cecil didn't allow a three-ball count all afternoon and finished with seven strikeouts over eight innings.

"I've really run out of things to say," Trembley said of the stagnant offense. "I've juggled the lineup. I've put different guys in there. We have really prepared our guys as best as we possibly can and it just hasn't happened for us. You got to still believe that perhaps tomorrow we'll get it started and I won't give up believing in that."