EAST RUTHERFORD, N.J. — Jerry Jones acknowledged before the game that he was “anxious” and “nervous” about watching the Dallas Cowboys’ season opener against the New York Giants.One of the last things he was probably concerned about was Dak Prescott. The franchise quarterback was part of the biggest play Sunday night at MetLife Stadium. It wasn’t a good one. His lone interception helped provide the Giants with a spark that eventually turned into a 28-20 Week 1 Cowboys loss.“That was crucial,” Prescott said. “I was trying to throw the ball away. The guy made a hell of a play. I got to make sure that it’s out of bounds, though. I was surprised. It’s one I want back, obviously. I think that was a huge point in the game.”Facing third-and-5 with just under a minute left in the second quarter and the score tied 7-7, Prescott was flushed out of the pocket, drifting 17 yards behind the line of scrimmage when he threw off his back foot.Giants safety Jevon Holland made a sliding grab near the Cowboys sideline. New York scored six plays later, taking a 14-7 lead into the halftime locker room. The Giants then received the second-half kickoff and scored again 12 plays later.What the Cowboys' disastrous season opener indicatesJon Machota“That was a big momentum swing,” Cowboys coach Brian Schottenheimer said of the interception.The Cowboys were never able to overcome that 21-7 deficit midway through the third quarter as they only had the ball for two possessions in the second half.Aside from the turnover, Prescott didn’t have a bad game. The Giants displayed a strong pass rush, but he was never sacked. He was accurate most of the night, even when he wasn’t getting much help early from his top playmakers.It was expected entering the season that with star wide receivers CeeDee Lamb and George Pickens, Dallas would simply pick up where it left off a year ago as one of the NFL’s best offenses.That didn’t happen Sunday night. Pickens had two costly drops in the first half, which was especially surprising because he was the Cowboys’ best training camp performer. He didn’t have two drops all of camp, but he had two on his first four targets against the Giants.The Cowboys’ top two offensive weapons had only 27 receiving yards in the first half, with most of their big plays coming from drawing defensive pass interference calls. Pickens finished with only three catches for 28 yards. Lamb totaled five for 44 yards and a touchdown.“It’ll get back to (clicking),” Prescott said. “Those guys had some uncharacteristic drops. I know that they’re upset about them immediately, came and made a comment about them and they moved on as they should. We’ll get back to it.”If they don’t, the season could quickly become a repeat of a year ago, because the defense still has plenty of issues.No one expected Christian Parker’s debut as defensive coordinator to go so poorly. Giants quarterback Jaxson Dart was outstanding, completing 23 of 29 passes for 230 yards and three touchdowns while also rushing for 54 yards on 11 carries.He never seemed rushed in his decision-making as he constantly appeared to have all the answers to the test. That’s concerning because that was a major issue for the Cowboys a year ago under Matt Eberflus, far too often opposing quarterbacks would have a career day against Dallas.Giants open season with win over Cowboys“This defensive unit is really good,” Cowboys defensive tackle Quinnen Williams said. “We got the guys to be accountable and get better. … We can be better and we will be better.”One of the biggest issues Sunday night was how easily the Giants were able to complete short passes into the flat for notable gains. That clearly bothered Schottenheimer.“You got young players,” he said. “Young player closes and Jaxson Dart boots and gets outside. We don’t push three different times the f—ing flat route, excuse my language. Those are going to happen and we’re going to have to coach the young players better, but when you play young players, it’s part of the deal. And they need to learn quickly.”Since trading Micah Parsons before the start of last season, the Cowboys have emphasized making roster moves that would help them stop the run. The Giants had little problem in that area, however, running 37 times for 165 yards and controlling the clock with relative ease.It appears the Cowboys have some quality pieces on defense, most notably Williams and rookie defensive back Caleb Downs, but the overall talent looked thin Sunday night. There were notable weaknesses on all three levels.“This is a humbling business,” Schottenheimer said. “We got humbled tonight. That’s what I told the guys. We lost Mile 1 of a 17-mile marathon.”What prevents him from watching that performance and thinking the defense was similar to last season?“Every day we went against them in practice,” Schottenheimer responded. “The defense we saw in practice was not what we saw tonight.”One game is too soon to panic. It’s realistic to think a team that doesn’t play its starters in the preseason could make a significant jump in Week 2. But there was too much bad to not be somewhat concerned.The offense has the weapons to put up points against any team, but the absence of standout left guard Tyler Smith was felt against the Giants, particularly in the run game early.“I’m still optimistic,” Prescott said. “That doesn’t change our goals. It doesn’t change how we feel about our team. This is a marathon. It’s a long season. We’re going to respond.”Defensively, the inside linebacker play wasn’t great and starting middle linebacker DeMarvion Overshown left the game early with a hamstring injury. Starting safety Malik Hooker left with what is feared to be a fractured forearm.Physically, the Giants had the edge. There wasn’t enough pass rush from the Cowboys and there weren’t many opportunities where Dart was forced to throw the ball into a risky space.Mentally, New York made fewer costly errors. Overshown hit Dart out of bounds early on a key play to get things going for the Giants. Running back Javonte Williams uncharacteristically held the ball out to a defender as he was crossing the goal line late in the game, leading to a taunting penalty that pushed back the point-after attempt from Brandon Aubrey, which he missed.Combine all of that and the recipe that beat the Cowboys on Sunday night will be copied going forward: keep their talented offense on the sideline as much as possible, establish the run game and put together long drives that eat up the majority of the clock. The Giants had the ball for more than 13 minutes longer than the Cowboys.Many have been skeptical of those singing the Cowboys’ praises for how quietly things were during the offseason. The vibe had been feeling different around the team for the first time in the last three years. There was a lot of positive momentum.But maybe this outcome just shows why Jones was feeling so anxious an hour before kickoff Sunday night.“I know the way we approach things,” Prescott said. “I know that our routine, I know that our standard, I know that the way we practice is the right way. My message is echoing, ‘Don’t change, don’t flinch, don’t blink.’ This is a long year. We have to stick together. We’re hanging our hat on our brotherhood and that’s who we believe that we are, so there’s no better time to show than after a loss.“A little bit of adversity, we got to make sure that we use it as a lesson.”