ATLANTA — It’s unusual for a rookie quarterback to make his first start in late December on a team still fighting for a playoff spot when the incumbent starter wasn’t injured. But that’s exactly what happened to the Atlanta Falcons on Sunday.

And Michael Penix Jr., the No. 8 pick in the draft last April, had a solid performance in the Falcons’ 34-7 win over the New York Giants here at Mercedes-Benz Stadium.

Penix was 18 of 27 for 202 yards and an interception, which wasn’t his fault. In the second quarter, he found tight end Kyle Pitts on a pass near the end zone. But Pitts let the ball wobble, and it was eventually intercepted by Giants cornerback Cor’Dale Flott.

The Falcons had 22 first downs, including 10 through the air. They were 8 of 14 on third down and 2 of 4 in the red zone, where they have struggled in recent weeks under former starter Kirk Cousins.

“He went out and played almost flawless football and really kept the game clean and made sure everything stayed clean for us so we could get a win,” Falcons coach Raheem Morris said.

Cousins ​​has nine interceptions with just a single touchdown pass in his last five games. The Falcons posted a 1-4 record in those games, including a four-game losing streak that lifted them from 6-3 to the pole position in the NFC South and clinched their playoff spot.

Cousins ​​has a league-best 16 interceptions and his 12 fumbles are tied for the most in the NFL with Baker Mayfield. Morris announced his move to Penix last Tuesday evening.

The Falcons are now 8-7 and the playoffs are within reach, although they are still mathematically the underdog to make it. In the remaining three games, the Tampa Bay Buccaneers, who they face in the tiebreaker, will have to make mistakes.

For a rookie quarterback starting in a must-win game for Atlanta, Penix showed a lot of poise. Even though the game against the Giants was played with two wins and the Falcons defense scored 14 points thanks to two pick-sixes. Running back Bijan Robinson had 94 yards on 22 carries and two touchdowns.

“I know I’m here for a reason,” Penix said. “I worked extremely hard to get to this position and I just had to go out there and execute and we did it to get a win today.”

Penix hadn’t worked much with the starting receivers in practice since Cousins ​​was QB1. So they had to ramp things up this week. Atlanta went on a walkthrough of 72 offensive snaps last Wednesday, and Penix threw every single one of them.

“It was a lot of work this week, man,” said receiver Darnell Mooney, who had five receptions for 82 yards. “A lot of work after training. During training, when we’re not on the offensive. So we still have to get better in many things. But like I said, things looked good today.”

When Penix got the call from offensive coordinator Zac Robinson that he would start for the Falcons, the quarterback was at Costco eating a hot dog. Penix said he won’t celebrate at Costco after his first career win as a starter. It will be “something edgier.” However, he’s still hoping for a Costco sponsorship.

“Costco is great,” Penix said. “Costco needs to talk to me.”