The 5-year-old chestnut gelding was clear at the head of the stretch and finished gamely to hold off favorite Mostacoli Mort by one length while covering 1 1/16 miles on Cushion Track in 1:41.91.
Barber, trained by Art Sherman for William J. Zellerbach, banked $30,600 to boost his earnings to $257,073. The win was his sixth in 23 starts.
Arambula, a 23-year-old native of Ventura who began his career riding quarter horses, also rode two winners Nov. 2 and has five victories through 12 days of the 40-day Autumn Meet. His first win Thursday came aboard Brave Sun ($8) in the third race.
Bejarano, who leads the standings with 15 wins, rode three winners on the card, while Doug O’Neill saddled a pair of winners.