Maggie Steffens scored three goals in the first half as the United States built a 5-2 lead over Spain midway through the gold medal game Thursday.
Heather Petri and Melissa Seidemann also scored for the Americans.
Jennifer Pareja had both goals for Spain.
In the bronze medal game, Australia defeated Hungary, 13-11, in two extra periods.
Maggie Steffens scored her 17th goal of the Olympic tournament, tying the score at 1 for the United States in the first period of the women’s gold medal game.
Jennifer Pareja had Spain’s goal, which bounced off the goal post and the head of U.S. goalkeeper Betsey Armstrong.
The U.S. women's soccer team goes for a third straight gold while Usain Bolt is aiming for double-gold in the men's 200 meters on another busy day of competition in London.
Croatia jumped out to a 5-0 lead midway through the second quarter and thoroughly dominated the United States in an 8-2 victory, eliminating the American in the quarterfinals.
The United States was hoping to at least match its performance from 2008, when it won silver in Beijing. Croatia is looking for its first water polo medal since winning silver in 1996.
Serbia used a furious fourth-quarter rally to overcome an early deficit and defeat Australia 11-8 in a men’s water polo quarterfinal.
The defending bronze medalists trailed 7-4 at the half but Andrija Prlainovic’s long distance goal midway through the third quarter triggered a 6-0 Serbian run to end the game.
Filip Filipovic had three goals to lead the way for Serbia, which awaits the winner of Italy and defending gold medalist Hungary.
Montenegro edged Spain 11-9 in an earlier semifinal. The United States – which won silver in Beijing – plays Croatia in the last quarterfinal of the day at 3 p.m. EDT.
Australia is halfway to a massive upset in the men’s water polo quaterfinals as they lead Serbia 7-4 at the half.
Jamie Beadsworth and Richie Campbell each had two goals in the first half for the Australians who at 2-3 were the only team with a losing record in group play to reach the quarterfinals.
Serbia, which won bronze in Beijing, is just 2 for 8 on the power play and changed its goalie during the intermission.
Carmelita Jeter goes for a second medal, Team USA faces Australia in men's basketball quarterfinals, and more on Day 12 of the London Olympics.
Spain will meet the U.S. in the women’s water polo gold medal game after edging Hungary, 10-9, in the semifinals on Tuesday. Anni Espar Llaquet scored four goals to lead Spain, which is in the Olympic final for the first time.
The U.S., which is also seeking its first gold medal in women’s water polo, needed overtime to beat Australia, 11-9, in the other semifinal.
The gold medal match will be played Thursday at 3 p.m. ET.
They had to work overtime, but the United States women’s water polo team is back in the gold medal game for the third time in four Olympics.
Maggie Steffens and Craig Kami scored in the first of two extra periods and the U.S. defense held Australia scoreless over six minutes to claim an 11-9 win.
The Americans led 9-8 with only one second remaining in regulation but the Australians were awarded a penalty shot when the referee ruled that the U.S. did not have possession when its coach called timeout. Ash Southern converted to force overtime.
Australia’s physical, end-to-end press took a toll on the American attack over the course of the game, but Steffens (4 goals) still had enough left in the tank to fire home what proved to be the game-winning goal midway through the first extra period.
Betsey Armstrong made 10 saves on 19 shots for the U.S. including a key tip over the crossbar moments after Steffens’ overtime goal.
The U.S. – which has never won gold – awaits the winner of today’s second semifinal between Spain and Hungary.
Three minutes separate the U.S. women’s water polo team and a return trip to the gold medal match.
Maggie Steffens gave her team a 10-9 lead on the power play midway through the first extra period with her fourth goal of the game.
On the other end American goalkeeper Betsey Armstrong made a stellar save on the ensuing possession, going full extension to tip a shot over the crossbar.
Kami Craig doubled the U.S. advantage, fighting off a defender and firing a shot past Victoria Brown to give the Americans an 11-9 lead.