The last-minute loss to Dallas didn't feel any better on Monday morning for the Giants. And it probably won't by Tuesday, Wednesday, or any other day in the near future.

Nonetheless, the 2015 season is still in front of Big Blue.

From forcing turnovers to players stepping up and having another crop of rookies make immediate contributions, there were plenty of positives to take away from Arlington despite the obvious regrets.**>> WATCH GIANTS VS. COWBOYS HIGHLIGHTS**

Here Giants.com looks at three things the Giants can build on as they prepare for the Week 2 home opener against the Atlanta Falcons:1. D FLASHED IN SPAGS' RETURN.

The final five minutes put a damper on Steve Spagnuolo's first game back as defensive coordinator of the Giants. In what was otherwise an encouraging debut for the new defense, the Giants held the Cowboys to 13 points in the first three quarters while taking a 10-point lead into the fourth. Six of them were on Dominique Rodgers-Cromartie's 57-yard fumble return for a touchdown that was originally forced by Trumaine McBride, who later grabbed an interception off a tipped pass and brought it down to the Dallas 1-yard line.

"We were fighting, we were playing together really well, we were rallying behind each other, rallying to the ball, playing physical, and I thought we showed a lot of good things out there," veteran defensive tackle Cullen Jenkins said Monday afternoon on a conference call. "The things that we just have to do better, we just have to get more crisp in our technique and our responsibilities. I think that, that really changed the bit of it, that fourth quarter, but we have to build off of that. What we put out there on the film is a start and it's something that we can build off of, and it's something that everybody has to look at positively, and understand that we can be even better, and even more dominant.

However, even Jenkins, who was one of four game captains for the Giants on Sunday night, needed a boost after the finish.

"We have to stay positive and rally together," Jenkins said. "I know it's tough and I know just for myself this is probably one of the toughest losses that I've had in my career. I found myself, even today, needing a boost. Some of the coaches helped pick my spirits up. [Hall of Famer Michael] Strahan was in the building and he talked to us and that helped a lot. It's things like when we just have to rally together, stay behind each other, and get through this together."

2. 'UNGA STEPPED UP.
Unsure that he would even be one of the top 53 players to make the roster last week, Uani 'Unga was thrust into the starting lineup in Week 1. He took over for middle linebacker Jon Beason, who was out with a knee injury, and did more than just hold his place. 'Unga led all players with 12 tackles (10 solo) and intercepted Romo right before halftime.

**>> QUOTES: ELI, COUGHLIN & CULLEN JENKINS**

"You know what, he played hard, he was aggressive, he made a lot of tackles," coach Tom Coughlin said. "He certainly got himself out of position a couple of times. But for a guy put in that position, I thought he responded very well."**

3. FLOWERS, COLLINS PASSED FIRST TEST**.
   Headlined by Odell Beckham Jr., the rookie class was a major storyline of the Giants' 2014 season. The 2015 class is trying to live up to it. First-rounder Ereck Flowers started at left tackle but had to fight through an early ankle injury that required an MRI. Meanwhile, Landon Collins, whom the Giants traded up to draft with the first pick of the second round, debuted at safety in an atmosphere that doesn't get much bigger for a season opener. The former Alabama All-American had four tackles, one of which was for a 2-yard loss on a Dallas run up the middle in the fourth quarter.

"Well I thought that they both played hard, and they both handled the situation very well," Coughlin said. "To be starting and playing in a game in the NFC East division, in Dallas, in their first regular season game—I thought they handled it very well."