The Aztecs (24-3, 14-2 Mountain West) shot 60 percent from the field, including 9 of 15 on 3-pointers, to cool off a Fresno State team that had won seven of eight. Quinn was 4 of 5 from long range to help San Diego State snap a two-game skid on the road.
It was the largest margin of defeat during conference play for Fresno State (15-15, 8-9).
San Diego State led by five at halftime and pulled away in the second half, particularly when Bulldogs top scorer Tyler Johnson went to the bench because of foul problems.
Winston Shepard scored on a runner in transition to give the Aztecs their first double-digit lead, 47-37, with 18:11 remaining.
The lead grew when Johnson went to the bench for a 2 1/2-minute stretch and San Diego State went on a 9-2 run to make it 56-43.
After Johnson re-entered, he quickly picked up his fourth foul with 12:07 remaining and took a seat again. And though Johnson came back in a few minutes later, San Diego State extended its cushion to 72-53 on Thames' 3-pointer with 6:19 left.
Johnson, who entered ranked third in the Mountain West with an average of 18.6 points, had a fairly quiet night until scoring six points in the final 4:21 to finish with 18. Marvelle Harris added 17 points for the Bulldogs.
Fresno State was trying to beat a ranked opponent for the first time since 2002.
At halftime, the school honored Hall of Fame coach Jerry Tarkanian, raising a jersey to the rafters as a sold-out crowd of 14,801 cheered loudly.
The Aztecs shot 61.9 percent from the field in the first half, including 5 of 8 behind the 3-point line. Fresno State shot 46.2 percent and went 4 of 8 from long range.
San Diego State led 40-35 at the break behind 11 points each from Thames and Quinn.
Harris had 11 points for the Bulldogs at halftime, while Johnson had four on 1-of-4 shooting.