Johnson was 6 of 8 from the field and added a team-high six rebounds for the Bulldogs (7-9, 1-2 Mountain West), who now have held 14 of their 16 opponents to fewer than 70 points.
Riley Grabau and Larry Nance Jr. led the Cowboys (14-2, 1-2) with 10 points apiece. The defeat, Wyoming's second in three games after a 13-0 start had them on the cusp of a Top 25 ranking, lacked the drama of the Cowboys' 63-61 loss to Boise State on a buzzer-beating 3-pointer.
Wyoming led 12-7 before a 10-0 run gave Fresno State the lead for good. The Bulldogs led by as many as 20 in the second half, and the Cowboys made just 12 field goals in the game.
Maryland point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.