Park clocked 1min 46.88sec, finishing almost two seconds ahead of the field.
Australian Ryan Napoleon was second in 1:48.66 and Japan's Yuki Kobori was third in 1:49.36.
Park opened the meet on Thursday with victory in the 800m freestyle, and won the 100m free and 400m free on Friday.
US superstar Michael Phelps opted not to compete in the final event of USA Swimming's Grand Prix series, swimming in Texas this weekend instead in his final tune-up for the US Olympic trials.
However, Santa Clara boasts a strong field of international swimmers gearing up for the London Games.
The women’s 200m backstroke featured a close Australian one-two finish with Meagen Nay winning in 2:08.04 and Emily Seebohm placing second in 2:08.88.
Canada's Hilary Caldwell was third in 2:11.41.
Australian Olympic gold medallist Stephanie Rice turned in a strong performance in the women's 400m individual medley.
She led the field throughout the race to win the event in 4:35.87. American Caitlin Leverenz made up a lot of time on the breaststroke leg, but was unable to overtake Rice. She placed second in 4:37.13 while China's Zhao Min finished third in 4:40.67.
Australian Bronte Barratt lowered her own meet record by 0.01sec in the women’s 200m free with victory in 1:57.17. Dana Vollmer was second in 1:57.25 and Japan's Hanae Ito was third in 1:58.05.
Yolane Kukla, 16, completed Australia's sweep of the women's individual events with a win in the 50m free in 24.97sec. American Madison Kennedy was second and Australian Libby Trickett third.
American Tyler Clary completed a tough double with victories in the men's 400m individual medley and 200m backstroke.
Clary won the medley in 4:15.02 ahead of Japan’s Yuya Horihata (4:16.27).
The American won the backstroke in 1:57.90, with Japan's Kazuki Watanabe second in 1:59.56 and Australia’s Ashley Delaney third in 2:00.14.
(For more sports news and updates, follow Ahram Online Sports on Twitter: @AO Sports)