The Lady Aztecs (23-11) upset two ranked teams to reach this game for the first time 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.
Cheek also added 14 points for Duke. The Blue Devils, who came in second nationally averaging 13.3 steals per game, nearly had that at halftime with 12. They finished with 23 and turned San Diego State's 26 turnovers into 32 points. Duke also improved to 25-2 when holding an opponent under 40 percent with the Aztecs
hitting just 37.7 percent.
"They were relentless," San Diego State coach Beth Burns said. "All credit goes to them. They certainly stepped up. They had something they wanted to get, and they went out to get it."
Quenese Davis led the Aztecs with 14 points. Jene Morris had 13, and Paris Johnson 12 before fouling out late.
The Blue Devils came as the Atlantic Coast Conference champ in both the regular season and the tournament. Their lofty pedigree and seeding didn't bother San Diego State for the first 20 minutes, not with the Aztecs having already knocked off Texas on its home court and third-seeded West Virginia just to reach this stage for the first time 1985.
The Aztecs didn't shy away from the speedy Blue Devils.
But Duke led 35-34 at halftime after a tight first half in which the teams swapped the lead back and forth 10 times with four ties. Duke led by as much as seven with seven straight points at 29-22 on a 3-pointer by Jasmine Thomas, who had 17 in the first half. She said she came out aggressive.
"I was pumped up, ready to play," Thomas said. "I mean I just read what the defense was giving me. Joy set a few more ball screens, and they played back off me so I took the shot that was open."
The tight game changed in the second half as the Aztecs lost their shooting touch. They missed their first 10 and hit only one of 13 before Quenese Davis' 3 with 8:05 left.
"They're really athletic and long," Morris said. "They closed really well. At times, we thought we had open looks, they were right in our face. They closed really well."
Duke didn't waste the opportunity. The Blue Devils opened the half with a 21-3 spurt in grabbing control, capped by Cheek's bucket with 8:18 left and a 56-37 lead. Thomas hit all six free throw attempts in that stretch to help pad the margin.