Boise State 42, Air Force 20: Jay Ajayi set career bests with 125 rushing yards and four touchdowns while Joe Southwick was 27-of-29 for 287 yards as the host Broncos defeated the Falcons in Mountain West Conference play.Ajayi scored on runs of 20, 35, 9 and 2 yards and Southwick passed for one touchdown, rushed for another and set a school record with a 93.1 completion percentage. Matt Miller had 112 yards on a career-high 10 catches for Boise State (2-1, 1-0 Mountain West).Quarterback Jaleel Awini rushed for 107 yards and two scores in his second career start for Air Force (1-2, 0-2). The Falcons were outgained 298-95 in the second half after playing the Broncos well in the first.Boise State led 21-17 at halftime and Ajayi scampered for his 35-yard score with 3:59 left in the third quarter to boost the advantage to 11. The Falcons pulled within 28-20 on Will Conant's 24-yard field goal with 10:56 to play, but Ajayi answered with a 9-yard TD run with 8:12 left to give the Broncos a 15-point lead and tacked on a short scoring run with 4:46 remaining.Southwick was 15-of-16 for 152 yards over the first 30 minutes. Awini rushed for 87 yards and a pair of 1-yard touchdowns in the half, but it was Southwick's 1-yard TD run with 24 seconds left that provided the Broncos with the four-point advantage.