ATLANTA — The Carolina Panthers have back-to-back playoff seasons for the first time in franchise history.

Back-to-back losing seasons could lead to a coaching change for the Atlanta Falcons.

Roman Harper and Tre Boston returned interceptions for touchdowns as Carolina’s defense led the Panthers to a 34-3 victory over the Falcons on Sunday to win the NFC South.

Carolina (7-8-1) will host Arizona in a wild-card playoff game next week. The Panthers have won four straight, but still are the first team to enter the playoffs with a losing record since 2010, when Seattle was 7-9.

Harper scored on a 31-yard return in the second quarter and Boston clinched the win with his 84-yard interception return late in the third quarter.

A 33-yard fumble return by Thomas Davis set up another touchdown.

The Panthers’ celebration began with their final timeout with 2:41 remaining.

Quarterback Cam Newton lifted his arms toward Carolina fans who moved close to the field to claim seats vacated by Falcons fans.

After the game, Newton answered fans who called his name by running back to the edge of the stands to give fans high-fives.

Newton completed 10 of 16 passes for 114 yards, including a 5-yard touchdown pass to Ed Dickson in the first quarter.

Newton also had a 4-yard scoring run.

The Panthers did not have a turnover.

The Falcons (6-10) were booed as they finished their second straight losing season under embattled coach Mike Smith.

Atlanta is 10-22 since falling to San Francisco in the 2012 NFC championship game.

Smith acknowledged the results have not met the standards he set with winning records in each of his first five years.

“This is a business about winning football games and that’s how you’re judged,” Smith said. “I understand that, and I’ll leave it at that.”

With a playoff spot — and perhaps Smith’s future — on the line, the Falcons committed three turnovers and were held without a touchdown.

Smith said he was “very disappointed” and called the performance “not acceptable at all.”

Carolina dominated the first quarter, running for 105 yards and holding the ball almost 12 minutes.

But the Panthers led only 10-3 before the defense stretched the lead.

Harper intercepted Matt Ryan’s pass intended for Roddy White and ran down the Panthers’ sideline for the touchdown.

On Atlanta’s next possession, White fumbled following a catch when hit by linebacker Adarius Glanton.

Davis picked up the loose ball and returned the ball to the Atlanta 9.

Newton’s touchdown run pushed the lead to 24-3.

Boston’s 84-yard return on his interception of Ryan’s fourth-down pass for Harry Douglas late in the third quarter pushed the Panthers’ lead to 34-3.

With star receiver Julio Jones contained by cornerback Josh Norman, Ryan couldn’t move the Falcons offense.

Ryan completed 29 of 47 passes for 260 yards with two interceptions. Jones had only four catches for 58 yards.

Falcons starting running back Steven Jackson was inactive with a quadriceps injury, and fill-ins Jacquizz Rodgers and Devonta Freeman were shut down.

Norman also was primarily responsible for holding Jones to six catches for 59 yards in Atlanta’s 19-17 win at Carolina on Nov. 16.

The Panthers improved to 15-3 in December games since coach Ron Rivera was hired in 2011.

It was a familiar setting for Newton and the Panthers, who also clinched their 2013 playoff berth with a Week 17 win at Atlanta.

The Panthers had nine sacks in that 21-20 win, and they were similarly effective with six sacks on Sunday.