Hall showed her strength to attack within one kilometre of the top of the penultimate climb to Daggett Summit, breaking clear with Tayler Wiles (Trek-Drops) from a select group that had formed on the ascent.
The pair worked together on the descent and the flat section, but Hall dropped her countrywoman on the final 1.5 kilometre climb to the finish in South Lake Tahoe, quickly gaining a gap and growing it all the way into the finish.
Wiles hung tough to finish second, with Katarzyna Niewiadoma (Canyon-SRAM) emerging from the chasing group behind to take third.
Australian Brodie Chapman (TIBCO-SVB) continued her impressive first year on the Womens World Tour, taking fifth on the stage, just over a minute down on Hall.
Hall goes into the final flat stage with a handy advantage of 29 seconds over Wiles, but will have bad memories from last year, where she surrendered the race lead on the same finish to Anna van der Breggen (Boels-Dolmans).
Coverage of the Tour of California continues for the final stage of the Mens and Womens events from 5.00 AM AEST on Sunday 20 May.