The Giants spent over $100 million this summer to improve its defense - and now it's starting to look dominant

Bill Kostroun/AP

Eli Manning turned the ball over three times against the red-hot Dallas Cowboys on Sunday night, the New York Giants offense managed 10 points on a meager 26o yards of total offense, and still the Giants won, 10-7, thanks to a masterful effort from a defensive unit that is emerging as one of the best in all of football.

It's been some turnaround for the Giants defense, which finished in the bottom-three in the NFL last season and is now giving up 18 points per game (seventh best in the league). The difference, of course, is personnel: after a disastrous 6-10 season saw the G-Men miss the playoffs, the team went out and spent over $100 million to improve on the defensive side of the ball.

On Sunday, that money looked well-spent.

Cornerback Janoris Jenkins, inked to a five-year, $62 million contract, was perhaps the best player on the field (his Pro Football Focus grade, 91.6, was the highest of any player in the game). The Jackrabbit, as he likes to call himself, picked off Dak Prescott and completely neutralized Dez Bryant, holding him to just one catch - which Bryant then fumbled, late in the 4th quarter, and gave the ball back to the Giants.

"That's why we brought him here" said safety Landon Collins of Jenkins. "That's why he gets paid what he gets paid. He wants to be great. Great players do great things."

Elsewhere in the secondary, Collins continued his much-improved sophomore campaign (PFF grade: 85.6), Dominic Rodgers-Cromartie (PFF grade: 85.1) broke up numerous passes and nearly picked off Prescott late down the stretch, and cornerback Leon Hall intercepted the Cowboys' rookie QB near the end zone and returned it for 29 yards. Even Eli Apple, the rookie cornerback out of Ohio State, has needed little time to adjust to the NFL; on Sunday he looked no more a rookie on Sunday night than Prescott did.

The secondary wasn't the only highlight. The defensive front was arguably even better, especially considering the venerable Cowboys offensive line, and Ezekiel Elliott in the backfield. Olivier Vernon, brought in from Miami on a five-year, $85 million deal this summer, and Damon Harrison, signed from the Jets on a five-year, $46 million deal, anchored a defensive line that held the kept Elliott in check (107 yards, but no scores) and contributed to Prescott's worst game as a pro.

Maybe most surprisingly of all, though, was the play of Romeo Okwara, a 21-year-old undrafted rookie free agent out of Notre Dame who started for the injured Jason Pierre-Paul. Okwara led the team with eight tackles, and picked up his first career sack.

"He played like JPP. So it's definitely unexpected," linebacker Jonathan Casillas said of Okwara afterwards. "You don't expect him or anybody to really do what (JPP) can do. And I feel like at least to a certain level, (Okwara) did that. That's huge."

The Giants have now won seven of their last eight games, and at 9-4 look poised to pick up a wild card spot.

The offense, meanwhile, is perplexing: no semblance of a run game, too many holding penalties, and - in spite of a great trio of wide receivers - still too many bad throws from Manning.

But if the defense can continue to look as confident as it did against the Cowboys on Sunday night, the flaws in the offense are easier to swallow. Plus, Odell Beckham Jr. is always a threat to go 60-plus yards for a touchdown - even on a simple slant, like he did to give the Giants the 10-7 lead.

Whenever a team spends as much money as the Giants did this summer, there will be doubts about whether it's worth it. Right now, it's paying dividends.