INDIANAPOLIS -- The moment of truth had arrived for the New England Patriots' defense in Super Bowl XLVI.

Leading by two points with 3:46 remaining, the unit was at the crossroads. Either stop the New York Giants from driving 88 yards to win a championship, or fail and go home empty-handed.

After 19 games of ups and downs, the formula was that simple.

"We were saying 'This is where we want the game,'" Patriots cornerback Sterling Moore said. "We want it on us. Somebody has to step up."

Well, nobody stepped up when it mattered most for New England's defense. The Giants marched down the field easily, in nine plays, and scored the Super Bowl-winning touchdown with 57 seconds remaining for a 21-17 victory at Lucas Oil Stadium. It was New York's second championship over the Patriots in four years.

The saying that "defense wins championships" still applied in the Super Bowl. The Patriots played hard and were scrappy defensively, but the group that was ranked 31st in the NFL this season couldn't hold it together for four quarters.

New York's final offensive drive was a microcosm of New England's season on defense. The Patriots gave up passing yards in bunches, starting with a 38-yard reception by Giants receiver Mario Manningham. Giants quarterback Eli Manning (296 yards, 103.8 passer rating) then proceeded to pick the Patriots apart with additional completions of 16 and 14 yards.

With time running out and Patriots quarterback Tom Brady on the sideline, coach Bill Belichick had no choice other than to let the Giants score the final touchdown to get the ball back to the offense. It was a helpless feeling in the biggest game of the year -- a feeling that New England's defense experienced several times this season.

The Patriots allowed 411 yards per game in the regular season and 396 yards in the Super Bowl. Similar to the regular season, New England did a decent job at keeping its opponent out of the end zone until the final drive. Nearly everything we saw from the Patriots' defense in this game held true to form from the regular season.

"I still feel like defense wins championships," a disappointed Patriots linebacker Brandon Spikes said. "We had our chances. We were right where we wanted to be on the defensive end, and I just feel like I let the guys down myself."

Spikes spoke about several missed plays he left on the field, but there were several big errors defensively in the game. The miscues started early when cornerback Antwaun Molden was the 12th man on the field in the first quarter. The play negated a fumble recovery by the Patriots and eventually led to New York's first touchdown.

There were two additional times the Patriots forced fumbles but teammates weren't around to recover them. New England played with maximum effort but seemed a step slow in big moments.

"Somebody had to come up with a play," Patriots linebacker Jerod Mayo said. "Somebody has to make a turnover."

There is good news for the Patriots: Help is on the way. The future could be bright for New England's weakest unit in 2012.

New England has plenty of cap space and early draft picks -- more than any team in the AFC East. The Patriots have approximately $20 million in cap room this offseason. Expect free-agent receiver Wes Welker to take a chunk of the pie. But after that, plugging holes on the defense is the primary focus.

The Patriots also have two first-round picks and two second-round picks in April thanks to recent trades. At least half of those picks should go to the defense, if not more. New England could use another pass rusher, a shutdown corner and another starting-caliber safety to pair with Patrick Chung. The Patriots have a golden opportunity to plug all these holes in the offseason.

There are some good defensive players already in place in New England. The linebacking corps of Mayo, Spikes and Rob Ninkovich is solid. Defensive tackle Vince Wilfork is still going strong, and defensive end/linebacker hybrid Mark Anderson is the team's best pass-rusher. But the Patriots could use upgrades to support these players..

Most importantly, New England needs big-time playmakers and game-changers on defense. That was never more evident than in the final minutes of Super Bowl XLVI.

"Obviously it's disappointing, but it's temporary," Mayo said. "We have a young team, great coaches. The core guys will be back and hopefully we can make another run. I know it takes a lot of work to get to this point, and hopefully we can get back. "

This Patriots were too incomplete and too one-sided. But expect this season's runners-up to be more balanced next season thanks to aggressive improvements on defense. Sunday's experience in the final minutes should also serve as fuel going forward.

"We will just remember this moment and remember how it felt," Spikes said. "We will be motivated by it. We can’t look back. ... It just wasn't our year."