Jasmine Thomas matched her career-high with 29 points, leading Duke to a 66-58 victory over the Aztecs.
With the win, the Blue Devils (30-5) notched their eighth 30-win season in the past decade and moved to the Memphis regional final, their first regional final since 2006 when they lost in overtime to Maryland in the national championship game.
This was the first time San Diego State (23-11) made it to this level since the tournament expanded to 64 in 1994. But the Aztecs' bid to become the first double-digit seed to play in a regional final since that expansion failed as they missed their first 10 shots of the second half.
Duke led 35-34 after a tight first half, and the Blue Devils scored the first 10 points of the second half to take advantage of the Aztecs' cold shooting.