PRINCETON, N.J.—On the weekend before Halloween, a treat almost seemed inevitable for Princeton.

The upstart Tigers—cloaked in orange and black and riding their longest winning streak since 1997—expected to pounce on a Harvard offense riddled by injury and weakened with uncertainty.

Then came the trick. Despite containing the Crimson offense, the Tigers couldn’t conquer the Crimson.

On this day, the defense was dressed up as Harvard’s most dominating unit.

“The defense deserves the lion’s share of the credit for getting us out of here with a [win],” said Harvard coach Tim Murphy of the unit that he has defended from outside critcism all year.

When Harvard was last in the league in opponents’ third-down conversions, Murphy said the pass rush would come.

When the Harvard secondary struggled against big-play receivers like Chas Gessner and Michael Sutton game after game, Murphy urged to give his players time.

It turns out that Murphy was right. Since a horrendous first-half performance against Cornell two weeks ago, the defense has allowed fewer game-breaking plays and made more of them each quarter.

Against Northeastern, the defense kept Harvard in the game until the Crimson’s potential winning drive ended with a Rodney Thomas fumble.

On Saturday—when four forced turnovers compensated for the Crimson’s lowest total offensive output in over a year—the defense won the game.

On Harvard’s first drive, Princeton disrupted the Crimson precision attack. Two false starts, a fumbled snap and two stuffed Ryan Fitzpatrick runs later, Harvard faced fourth-and-16 and a fired-up Tiger team.

Despite a beautiful punt by junior Adam Kingston, Princeton still took over in Harvard territory, 44 yards from a potential seven-point lead.

Then came the trick.

On second-and-five, Tiger star senior tailback Cameron Atkinson took the handoff and then took a monster hit from sophomore linebacker Brian Niemczak. The ball popped out of Atkinson’s clutches and was recovered by Armstrong at midfield.

Three minutes later, the good field position was transformed into a 7-0 lead.