Fresno State Junior Malik Sherrod had a career night rushing for 138 yards and two touchdowns, including ripping off a 62-yard touchdown run to give Fresno State a 7-0 lead with 9:19 to go in the first quarter.
Jack Browning made a 32-yard field goal about 4 minutes later and a 39-yarder on the first play of the second quarter before Jalen Mayden pulled the handoff on a zone-read and raced around the left end, down the sideline to make it 13-7 with 8:03 left in the second quarter and San Diego State (4-8, 2-6 Mountain West) led the rest of the way.
Browning added a 41-yard field goal about 5 minutes later before Dylan Lynch connected from 43 yards out as time expired to cut Fresno State's deficit to 16-10 at halftime.
Sherrod scored on a 1-yard run that made it a one-score game with 10:08 to play, but the Aztecs answered with a 14-play, 78-yard drive that took more than 7 minutes off the clock and culminated when Mayden hit Leo Kemp for a 5-yard TD with 2:54 left to cap the scoring.
Mayden was 17 of 26 passing for 189 yards and added 96 yards rushing on 14 carries. Jaylon Armstead scored on a 1-yard run that gave San Diego State a 23-10 lead in the third quarter.
Fresno State started the season with a record of 8-1 and in firm command of making it back to the Mountain West Championship Game to defend its 2022 title. But three straight losses ended the year, with the offense scoring just 18 points against San Jose State, 17 against New Mexico and 18 against San Diego State.
The Associated Press contributed to this report.