Las Cruces, N.M. ? Ian Johnson scored four first-half touchdowns and ran for 192 yards, and No. 18 Boise State toasted its debut in the BCS standings with a 40-28 victory over New Mexico State on Sunday night.

The Broncos (7-0, 3-0 WAC) earlier in the day landed at No. 15 in the first BCS standings of the season. They were solid offensively, but shaky on defense against the Aggies, who have lost 17 straight games against Division I-A opponents.

Johnson scored on touchdown runs of seven, one, three and 17 yards, and the Broncos finally put away the pesky, pass-happy Aggies with a pair of touchdown passes from Jared Zabransky in the second half.

New Mexico State (2-4, 0-2) kept it close behind sophomore quarterback Chase Holbrook, the nation’s total offense leader. Holbrook completed a school-record 49 of 65 passes for 526 yards.