The contest was a rematch of the famed gold medal match from 10 years ago in the first Olympics for women's water polo, which was played in the same venue.
Silver and Kami Craig each scored goals in the third period to give the Americans an 8-7 lead before the Aussies took control.
"It's always fun playing for first place and we had an idea of what we were up against with Australia but they are tough to beat," Silver said. "We will work more on our communicating and team defense with the aim of number one spot next week."
Craig was named tournament MVP, while Villa and Silver joined her on the all-tournament team.
Villa scored two goals in the American's 12-10 win over Greece in Wednesday's semifinals.
Stanford junior Melissa Seidemann and Cardinal sophomore Annika Dries each scored a goal as the U.S. played China to a 10-10 draw on Tuesday.
The Americans were using the tournament as a warm-up for the FINA World Cup, which begins Tuesday in Christchurch, New Zealand.
"Mentally, I don't think we were as ready as we could be. I take responsibility for this, but we'll be much better next week," U.S. coach Adam Krikorian said. "We'll have to play a lot better to be successful in Christchurch."
Anne Belden scored the last of her three goals with just over a minute remaining to play to tie the score as the U.S. squandered a 7-4 lead in the second period.
"She's had a great tour and played well," Krikorian said. "She was probably the one bright star for us."
The Americans were 3-of-4 on power plays while China was limited to 3-of-11.
The U.S. opens World Cup play with Russia and will also meet Australia and New Zealand in pool play. The Cup extends through August 22.
Junior Pan American Cup
In Pinecrest, Fla., the United States Junior National women's team beat Venezuela, 20-3, on the first day of the UANA Junior Pan American Cup.
The junior team features Stanford incoming freshman Kelsey Suggs and Stanford club team member Julia Peters.
The U.S. proceeded to beat Puerto Rico, 19-4, on Wednesday behind three goals from Suggs, and then beat Brazil, 15-4, as Suggs scored twice and Peters scored once.
Junior Olympics 18U
The NorCal 18U girls' water polo team didn't have much time to celebrate its best finish ever at the Junior Olympics in Los Angeles.
The group finished fourth in its age group on Sunday, flew home Monday and will be heading to the Hawaiian Invitational on Tuesday.
Come to think of it, a nice trip to Hawaii may be just the thing to help untangle those nerves and relieve the stress. Then again, NorCal is the defending girls' 18U and Women's Open champion in the Hawaiian event. A little business, a little R & R for a club which had its best previous finish in the Junior Olympics two years ago, placing 13th.
"By any measure this has been the most successful NorCal team ever," coach Chris Dorst said.
Atherton resident Hathaway Moore, who will be playing at Michigan in the fall, led NorCal (4-2-1) with 13 goals during the Junior Olympics. Menlo-Atherton grad Becca Dorst, headed for UCLA, added 12 goals. M-A senior Emily Dorst proved vital in the goal, making several significant saves.
NorCal opened its year with a championship at the BC (British Columbia) Open in January, followed by a third place finish at the Alberta Open, and a second-place showing at the Cal Cup.
The team opened the tournament with two wins, 19-1, over Modesto-Stanislaus, and 5-2 over the Florida Raider club.
NorCal followed that with a 20-0 pasting of Stanford White and tied Newport 7-7. The club won its bracket on a goal difference and advanced to the quarterfinals.
NorCal reached the semifinals with an 11-10 win over San Diego Shores, and then ran into the eventual champion LA Water Polo, losing 9-6. Santa Barbara edged NorCal, 8-7, in the third-place contest.
Other team members include Rachel Henry, who scored nine goals, Kelsey Nolan (7), Audrey Pratt (7), Jennifer Talbott, M-A grads Hannah Breen and Vanessa Lane, Kat Elward, Castilleja senior Barbara Peterson, Caitlin "KK" Sandlin, Allegra Tringali, Erin Glenn, and Sacred Heart Prep grad Heather Smith.
NorCal opened the Hawaiian Invitational with a pair of wins in each the Open and 18U divisions.
The NorCal women's open team downed Sunset, 10-6, and Agoura, 7-6, and will meet Anuenue A on Friday night at Iolani High.
The NorCal 18U team downed Iolani, 16-0, and SoCal East, 15-3. They are schedule to play a crossover match on Friday, also at Iolani High.
Junior Olympics 16U
The Stanford water polo club team coached by Kyle Utsumi recorded an overall finish of tenth in the platinum division.
Palo Alto's Skylar Dorosin led the team in scoring on the first day of the tournament, helping Stanford reach the second round unscathed.
Sacred Heart Prep's Pippa Temple was part of the reason Stanford won its third straight to open the tournament before falling into the 9-16 bracket after losing to Xtreme.
A shootout win over Santa Barbara, 7-6, it was 4-4 after regulation, put Stanford into the ninth-place game.
Stanford Red took a 4-1 lead over Pacific Zone rival 680 Drivers, but fell 9-6 to finish 10th.
"(Gunn's) Elizabeth Anderson drew the role of defensive stopper as we advanced through the tournament and did a great job," said Utsumi, who also credited Palo Alto's Martine Leclerc and Gunn's Lauren Lesyna with significant contributions.
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