That was the template for Harvard’s pattern of success as 17 of its 24 points came off of turnovers.

Trick: the defense forces a turnover.

Treat: the offense capitalizes and scores.

“You can’t win the game when you turn the ball over four times,” Princeton coach Roger Hughes said. “That is definitely a problem when you play a team like Harvard.”

As Hughes spoke during the post-game press conference, he sat facing a dry-erase board with a list of team goals scrawled upon it. Judging from his game plan, Hughes probably wasn’t expecting his quarterbacks to toss three interceptions.

The top three focal points were: “Physically dominate the secondary,” “Intimidate the secondary” and “[Make] big plays.”

Princeton did none of the three.

The Harvard secondary, easily the most maligned unit of the Crimson defense, finally contained a prime-time receiver. Senior Chisom Opara, the Ivy’s third-leading receiver, had a comparatively bland day of eight catches for 87 yards. More importantly, Opara’s longest catch went for only 20 yards.

Princeton’s longest play from scrimmage was only 31 yards.

Of course, there were mistakes.

The most notable muffed play came at the close of the third quarter when senior cornerback Chris Raftery got greedy and jumped in front of junior linebacker Juano Queen, who was standing in perfect position to intercept quarterback David Splithoff.

The pass, which would have been either defender’s second interception of the day, grazed off of Raftery’s fingers. The Tigers took advantage of the blunder to drive down the field and convert on a 30-yard field goal to cut the lead to two touchdowns.

In the fourth quarter, Princeton was able to string together its only extended drive of the afternoon, an 89-yard model of efficiency.

The march was highlighted by the scrambling of backup sophomore quarterback Matt Verbit and ended with a beautifully-thrown 16-yard TD pass to Opara.

The score cut Harvard’s lead to 24-17, and could have been a fatal error.

It wasn’t perfect, but it was a victory. And the victory was delivered, and finally secured, by the defense.

When junior defensive end Brian Garcia picked off Verbit with 14 seconds on the clock, he pulled in, with the ball, the credibility that Harvard’s defense has been seeking all season.

The Crimson offense was supposed to be carrying this team.

So, the trick? On Halloween weekend, the defense was leading the Ivy-title defense.

—Staff writer Lande A. Spottswood can be reached at spottsw@fas.harvard.edu.