Boise State couldn't overcome its rare mistakes on special teams.
The No. 19 Broncos, for years dominant on special teams, made two costly miscues against San Diego State that proved too much for their sputtering offense despite a late rally.
The Aztecs returned the opening kickoff for a touchdown then turned a blocked punt into another touchdown in a 21-19 upset at Bronco Stadium on Saturday night.
The defeat is a bitter one for the Broncos.
Coming into the game, Boise State had won seven straight and was inching toward a shot at playing in a BCS bowl. Now, the Broncos will need some help down the stretch to even have a chance of winning or sharing a conference title.
''This is my last year, and I know I'm speaking for all of the seniors, it kind of puts a damper on it,'' linebacker J.C. Percy said. ''We'll be all right though.''
The Broncos (7-2, 4-1 Mountain West) had a chance to tie the game late, but failed to convert on a 2-point conversion that would have tied the score...