The fans - many wearing black T-shirts with "FREE THE BIRDS" in white lettering - streamed into the stadium before the afternoon game chanting, "Sell the team!" and "Pete must go!" in a demonstration to voice their displeasure with club owner Peter Angelos.
Before filing out in protest an hour into the game, the fans, led by WNST-AM owner Nestor Aparicio, voiced a myriad of demands ranging from asking Angelos to sell the team outright, to somehow restoring the Oriole "magic" that existed before nine straight losing seasons.
There was frustration - almost a desperation - evident in the protesters' actions. "We want the magic back," said one placard. Several times, the demonstrators began cheers for long-departed Orioles star Eddie Murray ("Ed-die, Ed-die") and for the late Elrod Hendricks.
"That's appreciated," Angelos said of the fans' regard for the team's past.
But Angelos, reached at his law office, said he was disappointed at the personal nature of the criticism from Aparicio, whom he called an "instigator" and a "demagogue."
Angelos, an attorney who bought the club in 1993, said the protesters may have been "misguided" and suggested some critics don't understand the cost and complexities of owning a ballclub.
"I wasn't directing that [remark] at the participants but at the instigator, who has been ranting and raving very personally at me," the owner said. He said he was "shocked" that Sun columnist Rick Maese had written a piece Wednesday in which he said the protest "could ultimately serve as a benchmark" for how fans feel.
"For [Maese] to incite this fool, this demagogue, I was shocked to see that ... from a respectable newspaper," Angelos said.
Hours before the game, Aparicio, drinking a beer and wearing one of the protest's specially made T-shirts, greeted fans at the outdoor deck at the Hard Rock Cafe before leading them on a noisy march through the Inner Harbor to the stadium. He said the Orioles' organization had become an "embarrassment" and that it was time for Baltimore to make a statement.
"Get some players in here who want to be part of the community, who understand what a crab cake is. How about they know where Dundalk is and they know where Catonsville is?" Aparicio said. He was joined at the protest by his 87-year-old mother, who said she never misses an Orioles game on television.
After arriving at the stadium, the demonstrators headed for the upper left-field stands - their organizers had encouraged them to buy the cheapest possible seats - where they cheered Orioles players and recited their demands in chants and media interviews conducted in the stands.
Many fans asked that Angelos restore the city's name to the club's road jerseys.
"That's not a request that's improper or unjustified," Angelos said. "Now there is a National League team in Washington, so obviously the distinction [between the cities] should be made."
At 5:08 p.m. - a nod to former Orioles greats Brooks Robinson (No. 5) and Cal Ripken (No. 8) - the fans got up and headed for the concourse. At the time, the Orioles trailed 3-1 and had runners on second and third in the fourth inning with nobody out.
"It's weird leaving," said Mike Liberto, a partial season-ticket holder. "I've never left, at least not until the seventh inning when they stopped selling beer."
The protesters had filled parts of sections 380 through 388 in the upper deck. Though there was no official count, the demonstrators said there seemed to be several thousand. Police and the media estimated the number between 800 and 1,200. Organizers had originally hoped for 5,000.
The demonstrators were the noisiest fans in the park, cheering the players loudly and spelling out "O-R-I-O-L-E-S."
"We are on the same page. We share that same passion and exuberance," said Mike Flanagan, president of baseball operations.
"I don't think for the most part, people can comment on who should own a club or who shouldn't own a club," Flanagan said. "What came through loud and clear to me is that they are passionate Orioles fans. They want to win. We want to win. I want to be here and have races in September that mean something and have that kind of cheering in the stands again. It's been too long."
Players noticed the demonstrators' enthusiasm, too.
"I think anytime your fans show that they care, that's good," second baseman Brian Roberts said. "They showed they care about our organization, they care about the team, they care about winning. Now, what they were trying to accomplish, I have no idea."
Sun reporters Dan Connolly and Childs Walker contributed to this article.