JACKSONVILLE, Fla. (AP)Dak Prescott sat sprawled on the Jacksonville grass, having been knocked to the ground while trying to make a game-saving tackle, and watched in disbelief as safety Rayshawn Jenkins sprinted by for a touchdown in overtime.

It was a helpless feeling that followed another costly mistake.

The Dallas Cowboys backed into an NFC playoff spot Sunday night when the New York Giants beat Washington, but their stunning collapse at the Jaguars could prove to be a pivotal moment for them this season.

Jenkins intercepted Prescott’s tipped pass intended for Noah Brown and returned it 52 yards for a score and gave Jacksonville a 40-34 victory Sunday that few saw coming.

”Yeah, frustration grows, obviously,” Prescott said. ”To end the game on a pick-6, yeah, it’s tough. It’s tough. It’s frustrating. … Obviously, I’ll learn from it and tuck it next time. It’s tough. It’s tough treading that line, trying to make a play, trying to be aggressive, and at the same time not putting the ball at risk.”

Prescott completed 23 of 30 passes for 256 yards, with three touchdowns and two second-half interceptions. The turnovers led to 14 points that helped the Jaguars rally from a 17-point deficit.

Dallas had won 39 in a row when leading by at least 17 points, and Prescott had been 30-0 as the team’s starter with that kind of lead.

”I take every loss on the chin,” Prescott said. ”I think that’s my job as a quarterback – to put us in positions to win and eliminate the mistakes and the potential chances to allow them to score after turnovers.

”That’s what’s frustrating about it, whether it’s a tipped ball, whether it’s an unfortunate interception, whatever it is. They all suck, and at the end of the day, I’ve got to do a better job, and that’s where it is.”

The Cowboys had won four in a row and looked as if they were well on their way to clinching consecutive playoff berths for the first time since the 2006-07 seasons. They scored touchdowns on two of their first three possessions and led 21-7 at halftime.

But third-quarter woes gave Jacksonville an opening. Dallas settled for a short field goal after having first-and-10 at the 12 and then Prescott threw his first interception. Equally troubling for Dallas was having a chance to seal the victory after forcing Trevor Lawrence to fumble with a minute and a half remaining and failing to pick up a first down.

Prescott even threw deep on third down, allowing Jacksonville to save a timeout for its game-tying drive that set up Riley Patterson’s 48-yard field goal at the end of regulation.

”We’ll just keep working and keep plugging,” Cowboys coach Mike McCarthy said. ”I’m not going to sit here and just keep diving into it. I get the reason for the question, all that, but he’s trying to do it the right way that’s for sure.”

Despite the gut-wrenching loss, Dallas ended up landing a playoff spot thanks to the rival Giants and can rebound next weekend by beating NFC East champion Philadelphia. That would at least erase some of the sour taste left over from the franchise’s first game in Jacksonville since 2006.

”It’s about at this point building, trying to get better, trying to clean up our mistakes, learn from our mistakes and make sure that we’re just carrying momentum heading into week after week as we move forward to get into this postseason,” Prescott said.

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