ARLINGTON, Texas — The way it started for Saquon Barkley, it looked like Sunday was going to be a glorious, productive — winning — season opener.

On the second play from scrimmage, Barkley burst through a gaping hole on the left side of the offensive line and rambled for 59 yards to the Dallas 23-yard line. Four plays later, the Giants, a touchdown underdog, were leading on the road, 7-0, on an Eli Manning scoring pass to Evan Engram.

Then, as the afternoon progressed and the game began to get away from the Giants — resulting in a 35-17 Cowboys win at AT&T Stadium — Barkley disappeared.

One of the top two or three running backs in the NFL touched the ball twice in the second quarter as the Cowboys built a 21-7 halftime lead and began to bleed this game away — from the Giants and Barkley.

Barkley would finish with 120 rushing yards on 11 carries and he caught four passes for 19 yards. But 15 touches in a game from the team’s best player is not a winning formula for the Giants.

“Games play out differently,’’ coach Pat Shurmur said. “He had really good production when he touched the ball … and we threw it to him, too.’’

Yes, but not enough.

The most questionable sequence in the game as it related to Barkley came in the third quarter with the Giants trailing 28-10 and with a third-and-2 from the Dallas 8-yard line. Manning handed the ball off to Eli Penny, who entered the game with 149 career rushing yards, and he gained 1 yard.

Fourth-and-1 from the 7-yard line, Barkley returned to the backfield and a pass play was called for Manning to roll out to his right and he ended up fumbling.

That was pretty much it for the Giants.

Shurmur defended the play calling.

“We should have gained more yards on the [play] to Penny,’’ he said. “And then we’ve got to do something with the ball on fourth down.’’

Barkley second-guessed nothing.

“Obviously, as a competitor you want the ball in your hands, but you’ve got to trust the system. You’ve got trust your teammates,’’ he said. “It’s what I do. I’m not going to question the call. I believe that the calls are right, and we have to find ways to capitalize on them, convert that third down and convert that fourth down and find a way to get into the end zone.

“We’ve got to find ways to make it happen. We’ve got enough playmakers on offense that can help our defense out.’’

He also defended the fact that he had so few touches.

“They got up on us with a pretty big lead, so it’s hard to run the ball when you’re down,’’ Barkley said. “My mindset is to continue to get better, and however many touches I do get to make the most of them to help my team win. I didn’t do that today. We’ve got to get better.’’