PULLMAN — Washington State’s offense was so putrid for most of the 20th-ranked Cougars’ marathon game against Boise State on Saturday night that Mike Leach called his offense’s performance “pathetic” and accidentally let an expletive slip in a halftime radio interview.

But on this bizarre night, the WSU defense was every bit as good as its offense was bad, and it was on the strength of this defense that WSU somehow found a way to rally from a 21-point fourth-quarter deficit to beat Boise State 47-44 in triple overtime.

WSU defensive coordinator Alex Grinch’s Speed D forced three turnovers and scored on two interception returns, and held the Broncos to two field goals in the first and third overtimes to keep the Cougars in a fight their offense seemed determined to lose.

Win they finally did, though, in triple overtime, behind backup quarterback Tyler Hilinski, who entered early in the fourth quarter in place of an injured Luke Falk and played the game of his life.

Hilinski finished 25 of 33 passing for 240 with three touchdowns. That third touchdown was the magical game-winner — a short pass to running back Jamal Morrow from the 22-yard line.

Morrow shed one Boise State defender, then scurried upfield and dove for the end zone, falling out of bounds as he did so.

The play was ruled a touchdown, but then reviewed.

Luckily for the Cougars, it stood up as a score to complete their crazy comeback. The 32,631 spectators at Martin Stadium erupted, and the student section rushed the field in elation.

It was Hilinski who sparked the Cougars to two fourth-quarter touchdowns to rally them from a 31-10 deficit to send the game into overtime.

Then, in overtime, Hilinski managed to get the offense within a yard of the goal line. But, as had been the case all night long, the Cougars could not finish. James Williams was stopped a yard shy of the end zone, Morrow was stymied for no gain, and on third-and-goal, Isaiah Johnson-Mack dropped a pass that hit him in the chest in the end zone.

The Cougars settled for 22-yard Erik Powell field goal.

The Cougars put their defense on the field first in the initial overtime period, and just as it had all night, Grinch’s squad came through. Peyton Pelluer, who scored the game-tying pick-six in the fourth quarter, had two huge stops, and Derek Moore harassed Boise State quarterback Montell Cozart into throwing the ball away on third-and-9 to force the Broncos to settle for a 29-yard field goal.

On a night when Falk set WSU career records for passing yards and offensive yards, he also struggled enough that he was benched for Hilinski for one series in the third quarter, and then re-entered the game only to get knocked out of the action entirely after he took a hard hit from BSU’s Jabril Frazier at the start of the fourth quarter.

Despite all this drama, the Cougars took the field behind Hilinski with 2:51 left in the fourth quarter, trailing Boise State only 31-24 in a game in which they never led until the second overtime period.

Down 31-10 at the start of the fourth quarter, with a ton of help from the Cougars’ defense and a big dose of luck on special teams, WSU somehow found a way to rally.

The Cougars punted for the sixth time of the evening with just less than three minutes left, after yet another ineffective offensive drive in a night full of Air Raid misfires.

But the punt hit Boise State’s Reid Harrison-Ducros in the back of the helmet, and Dillon Sherman recovered to give WSU the ball at BSU’s 24, with 2:51 left.

Hilinski connected with Tavares Martin Jr. for 4 yards, then hooked up with Johnson-Mack to pick up 14 and get the Cougars to Boise State’s 6-yard line.

Two plays later, Hilinski found Morrow on a 6-yard touchdown pass, and Erik Powell’s extra point tied the game at 31-31 with 1:44 left.