The Mustangs (2-0), a FCS school, improved their record to 4-12 against upper-division teams over the last 10 years.
Wyoming (0-3), playing without injured quarterback Brett Smith, struggled offensively all day but led 15-14 at the half.
Cal Poly reclaimed the lead, 21-15, on a 5-yard pass from Andre Broadous to Kristaan Ivory late in the third quarter. Bobby Zalud’s 51-yard field goal with 9:49 left put the Mustangs up 24-15 and proved to be the difference.
Shaun Wick’s third score of the day, a 14-yard rush, drew Wyoming within 24-22 with 7:34 left. But the Cowboys could not gain a first down on their final two drives, the last ending in an interception by Cal Poly’s Nico Molino.
Williams’ 187 yards, a career-high in a Mustang uniform, came on 19 carries. He reeled off long runs on Cal Poly’s first two possessions, leading to a 14-0 advantage with just over five minutes gone. The first was a 65-yard TD and the second a 74-yard scamper that set up Ivory’s 9-yard scoring run.
For quarterback Colby Kirkegaard’s first start, the Cowboys employed a conservative approach, limiting long passes and relying more on the running game. Wyoming punted after its first four drives, but Kirkegaard completed his last eight passes of the first half and led the Cowboys to consecutive scores in the second quarter.
A 37-yard punt return by the Cowboys’ Jalen Claiborne set up a 1-yard TD plunge by Wick, followed by a successful two-point conversion that drew Wyoming within 14-8. Wick scored again from one yard out just before intermission to give the Cowboys a 15-14 lead.
Cal Poly outgained Wyoming 359-260. The Cowboys entered the contest ranked 98th in total defense, yielding 431 yards a game.