The third seed, who received a bye in the first round, beat the American wildcard 6-3 6-1 in just over an hour.
Konta, the world number 18, hit 11 aces on her way to a comfortable victory.
The 25-year-old will play China's Saisai Zheng, who beat Alize Cornet in her second-round match, in the last eight on Friday.
British number one Johanna Konta reached the quarter-finals of the Bank of the West Classic in Stanford with a straight-set win over Julia Boserup.