BOISE, Idaho — A perfect season.

A perfect moment.

An imperfect system.

All were part of the story Friday night at Bronco Stadium as the No. 9 Boise State football team capped its third undefeated regular season in five years with 48 second-half points to bash Fresno State, 61-10.

The season? So dominant that the Broncos led for every moment of every second half in all 12 of their games.

The moment? Senior tailback Ian Johnson — showered with chants of "Ian! Ian!" — delivered his best game of the year and the WAC-record-tying 57th rushing touchdown of his career.

The system? That was the villain in an otherwise fairy-tale day — because as powerful as the Broncos looked against the Bulldogs, they almost certainly will be left out of the Bowl Championship Series party when the selections are announced Dec. 7.

Instead, the Broncos likely will receive a nice consolation prize — a trip to the Dec. 23 Poinsettia Bowl in San Diego to face No. 14 TCU (10-2). No bowl decision is expected until at least Tuesday.

"We didn't set out for a BCS game," Boise State coach Chris Petersen said. "That wasn't it. Our deal was to finish every game, play as hard as we can and win the WAC championship and good things will happen to us. And they will." The Broncos certainly used the ESPN2 stage to send a message Friday — turning a game they led 13-10 at halftime into a rout with four touchdowns in the first 10 minutes of the second half.

The Broncos scored on a 43-yard run by Jeremy Avery, a 90-yard punt return by Kyle Wilson, a 35-yard reverse pass from wide receiver Tanyon Bissell to Julian Hawkins and a 16-yard pass from quarterback Kellen Moore to Tommy Gallarda. In between, the defense grabbed interceptions on two straight Fresno State offensive plays. All of a sudden, Boise State led 41-10 with 5 minutes, 10 seconds left in the third quarter.

"We thought we were in it going into the third quarter, and the thing just got out of control," Fresno State coach Pat Hill said. "I've never had a game get out of control like that." Then the Senior Day fun began.

Johnson, who became the most famous Bronco ever as a sophomore star on the 2006 Fiesta Bowl team and endeared himself to his coaches with his selfless approach to a limited role as a senior, busted a long run on the last play of the third quarter. He made a couple of moves, broke to the right sideline and dragged cornerback Damion Owens 18 yards to the Fresno State 4-yard line. He was winded, but the quarter break gave hi time to recover.

He scored from 4 yards out on the next play for his rushing 56th touchdown.

Johnson contributed 13 yards on the Broncos' next possession and the crowd started chanting his name. On second-and-6 at the 8, freshman Doug Martin replaced Johnson.

The crowd booed.

Martin, though, played his part perfectly. He bolted up the middle but was tripped at the 1.

Johnson trotted onto the field and easily scored the record-tying TD.

Johnson finished with 128 rushing yards — his first 100-yard rushing game of the year and the 16th of his career — and 39 receiving yards.

"It was awesome for Ian to end this thing (that way) on the blue," Petersen said. "It was perfect." Johnson still needs one more touchdown to break the record, which is held by legendary San Diego State/St. Louis Rams running back Marshall Faulk. The Broncos could have gotten it for him Friday, instead letting sophomore D.J. Harper score the last touchdown.

"We've got another game," Petersen said. "Hopefully he gets it done there." Johnson's big night overshadowed what has been the overriding theme for this year's Broncos — a stifling defense.

The Broncos defense only allowed three points to the Bulldogs (the other seven were on an interception return) and 67 offensive points in eight WAC games.

"They're phenomenal," Petersen said. "... This is a special, special defense. Those guys played their tails off. I'm just really pleased with how consistent they played every game against whatever style of offense was thrown at them." It was a season of redemption for the defense, which allowed 80 points in the last two games last season — losses in the WAC title game at Hawaii and the Hawaii Bowl.

"Last year is still a very sour taste in everyone's mouth," Wilson said. "It's like yesterday. Nobody wants that feeling again." In fact, that feeling will continue to drive the Broncos for the next month.

Yes, they are WAC champs. Yes, they finished the regular season the way they wanted.

But no, they aren't done. The top of their pyramid of goals is one word: "Finish." ''We took a little part of the pyramid but still, if you don't finish that bowl game, I don't think anybody will be satisfied with this season," Wilson said.

They aren't applying the same rule to the BCS.

Still, it's clear the Broncos think they belong at that level.

"You guys saw," Wilson said. "We're ready. We'll play anybody."