NEW ORLEANS (AP) — Undrafted rookie quarterback Tyson Bagent and the Chicago Bears had their way with one of the top-rated defenses in the NFL for nearly three quarters.

Then, suddenly, they couldn’t cross the 50-yard-line.

Bagent, who threw two of his three interceptions and lost a fumble on a sack in a nine-minute span of the fourth quarter, blamed himself for the Bears’ offensive implosion in a 24-17 loss to the New Orleans Saints on Sunday.

Chicago, which lost the turnover battle 5-0, never got past its own 35-yard line in five series after tying it at 17 on Cairo Santos’ 31-yard field goal with 3:27 left in the third quarter.

“It all comes to me in that last quarter being able to do a better job of taking care of the ball,” Bagent said.

Coach Matt Eberflus “talks about how important it is every single day,” Bagent added. “It was basically just me (making mistakes) there in that last quarter.”

Making his third straight start in place of an injured Justin Fields, Bagent was 15 of 19 for 201 yards with two touchdowns through three quarters. He went 3 of 11 for 19 yards with the three turnovers from there.

Two plays after the Saints went ahead 24-17, safety Marcus Maye made a diving interception of a pass Bagent said he threw late over the middle. After Chicago stopped Derek Carr on a fourth-down sneak at their 17, Bagent was picked off by cornerback Paulson Adebo.

“It was good on their part and bad on my part,” Bagent said. “Tight coverage, and they made a couple of really good plays. Hats off to them, but I have to probably go somewhere else with the ball.”

Chicago’s defense kept giving the offense more chances, but it could not take advantage.

The Bears failed to pick up a first down after the Saints downed a punt at the 2, and they turned the ball over following a missed 47-yard field by Blake Grupe with 2:27 left that kept them in the game.

The Saints then ran out the clock in a bizarre fourth quarter in which all 34 plays run by both teams started in Bears’ territory.

“We came kind of to a screaming halt there,” said tight end Cole Kmet, who had touchdown catches on two of Chicago’s first three possessions. “I don’t know if it ever happened before where they are on our side of the 50 for the entire fourth quarter. I’ve never seen that in my life.”

Kmet capped the Bears’ opening drive by outfighting safety Tyrann Mathieu in the end zone for an 18-yard grab. Bagent hit Kmet again for a 9-yard score in the second quarter for a 14-7 lead.

Bagent scrambled eight times for 70 yards, running back D’Onta Foreman gained 82 yards on 18 carries through three quarters and the Bears had outgained the Saints 348-171 at one point.

“It’s frustrating because there were some opportunities to really extend the lead,” Kmet said. “I really think Tyson played great, and I think the film will show that. We can do better as a skill group for Tyson in terms of being more friendly with the routes and making more plays for him.”

The Bears lost by only one touchdown despite their five turnovers and getting penalized eight times for 71 yards to the Saints’ one flag for 5 yards. Those negative numbers prompted some positivity from Eberflus, who also lauded the addition of defensive end Montez Sweat.

Sweat, acquired in a trade with Washington this week and signed to a long-term contract extension Saturday, had two tackles and broke up a pass in his first game. He has 35 1/2 sacks in 4 1/2 seasons.

“We’re all excited,” Eberflus said. “You add a pass rusher to your defense, that’s a big deal for us going into our future.”

The immediate future may not include Bagent, who is 1-2 in three starts a year after playing for Division II Shepherd College. Fields, who practiced on a limited basis Friday, might be activated Thursday when Chicago hosts Carolina.

Bagent “had really good moments in the starts that he’s had, and he’s got to build off of that,” Eberflus said. “The most important thing Tyson can do now is learn and get better.”