The Serbs outmuscled the Americans on both ends of the pool, got a string of solid saves from goalkeeper Slobodan Soro and used sharp shooting and a quick counter in the attack to beat the U.S. 11-6 Saturday at the Olympics.
"We mentally weren't there," U.S. captain Tony Azevedo said. "We came out thinking that maybe they weren't going to come out as hard, or maybe we were just going to spark automatically. But you know, you got to take the bull by the horns and we didn't do that today."
With the loss, the Americans' first at the London Games, the U.S. falls one point behind Serbia, which leads Group B with seven points. Serbia can wrap up the group's top seed in the quarterfinals by beating Romania in its last preliminary-round game.
Serbia led from start to finish Saturday, with Vanja Udovicic scoring his first of three goals only 33 seconds into the game as the 2012 European champions ran up a three-goal lead to take control early. The Serbs then put the Americans away with another three-goal surge to open up an 8-3 gap in the third quarter.
"They beat us soundly, for sure," U.S. coach Terry Schroeder said. "They're a great team."
The U.S., which has already guaranteed itself a spot in the quarterfinals, plays three-time defending champion Hungary in its last group game on Monday.
"Serbia's a great team, they're very good. Clearly right now they're the favorites," Azevedo said, but added that the Americans did not play to their strengths on Saturday.
"We're known for not giving up counter goals, set goals, and putting away our six-on-five, and we did the opposite today. We gave up six counter attack goals—that's unheard of," he said.
A Serbia victory against the U.S., in recent years at least, is far from unheard of. The Serbs have dominated the Americans at major competitions since 2008, winning six of seven meetings.
In a bright spot for the Americans looking ahead in London, however, the sole U.S. win over that stretch came in the semifinals of the Beijing Olympics, where the U.S. avenged a preliminary-round loss by beating Serbia 10-5 to advance to the final.
The U.S. eventually lost to Hungary 14-10 to earn a silver in 2008.
"I think in all our minds we know that Serbia is maybe the best team here, and beating them twice is going to be very difficult for sure," Schroeder said. "So I just hope that we get another shot at them down the road."
If the U.S. wins its quarterfinal game, it could meet Serbia in either the semifinals or the final, depending on how the brackets shake out for the knockout stage.
The big question at the moment is whether the U.S. is even playing at a level that's going to give them another shot at the Serbs. The simple answer from Azevedo: No.
"We definitely have to pick up our game. We're not going to win a crossover game playing like we are right now," he said. "We definitely need to be better as a team, all of us, defensively take responsibility for everything and move forward."
After opening their Olympic campaign with a quality 8-7 win over a very talented Montenegro team, the U.S. played just well enough to beat the two weakest sides in the group, Romania and Britain. But their form was far short what they'll need to advance deep into a tournament that boasts a lengthy list of legitimate medal contenders.
Two other teams, Montenegro and Hungary, both won their Group B games earlier Saturday to join the U.S. and Serbia in the quarterfinals.
Aleksandar Ivovic scored three times for Montenegro to beat Romania 12-8. The 2012 European championship runner-up, Montenegro has impressed so far in London, recovering from an opening loss with the U.S. to beat Hungary and then draw with Serbia.
Montenegro plays winless Britain in its final preliminary-stage game Monday.
Hungary, which dropped its first two games before squeaking out a tough win over Romania on Thursday, advanced to the quarterfinals by beating winless Britain 17-6 behind four goals from Tamas Kasas and Norbert Madaras.
While the four teams that will represent Group B in the quarterfinals are set, the seeds are still very much up in the air.
The men's field is broken into two groups of six teams. The top four from each group advance to the quarterfinals.
On the other side of the bracket, Croatia stayed unbeaten and secured the top spot in Group A with its 11-6 win over Australia. Two other teams in Group A—Spain and Italy—also wrapped up spots in the quarterfinals.
Filipe Perrone Rocha scored twice to push Spain past Greece 11-9, while four players netted two goals for Italy in a 9-6 win over Kazakhstan.
Spain plays Italy in their final group game Monday, and the winner will earn the No. 2 seed out of the group for the quarterfinals. Spain can also secure the second spot with a draw.
Greece has just two points from four games, but can still advance by winning its final preliminary-stage game Monday against Australia.
Ryan Lucas can be reached on twitter at http://www.twitter.com/relucasz