CHARLOTTE — The Panthers knew they were working with fine margins, going into a game with a pair of starting cornerbacks who were just elevated from the practice squad.

And when a controversial call took away a shot to build on a lead in the third quarter, the Broncos took advantage.

The Broncos beat the Panthers 26-21 Sunday at Bank of America Stadium, when the game swung late in the third quarter on a controversial interception in the end zone, and a late sack-fumble which continued some recent protection issues.

That was their third straight loss, and dropped them to 3-5.

The Panthers appeared to be in position to build on the lead late, with a 14-13 edge and the ball at the Broncos 1.

What looked like an incomplete pass to Tommy Tremble (which could reasonably be argued was preceded by some pass interference) was overturned on review, when it was ruled the ball hit Tremble's foot and not the ground before it was controlled by Denver safety Devon Key.

But the Panthers believed the challenge flag from Broncos coach Sean Payton was too late, since Chuba Hubbard had already run the ball on second-and-goal from the 1.

But officials said Payton got the challenge in on time, and then reversed the call on review (pass interference hasn't been reviewable since a one-year experiment in 2019).

The Broncos responded with a long touchdown drive, going 80 yards in 14 plays, but missed the two-point conversion attempt for a 19-14 lead with 10:17 left in the game.

Jonah Coleman capped it with a 9-yard touchdown run, past the diving tackle attempt of Corey Thornton.

And when the Panthers got the ball back in the final two minutes with a chance to win, Bryce Young lost the ball as he was sacked by Nik Bonitto, who got around left tackle Rasheed Walker.​

That spoiled a day when so many other things appeared to be going their way.

Despite the Broncos targeting practice squad cornerbacks Thornton and Marco Wilson early, the Panthers defense caught its breath and made nearly enough stops. Whether it was Chau Smith-Wade breaking up passes (he had a pair in the end zone), or a Patrick Jones II sack, there were moments when it appeared this week's changes were paying dividends.

And other than the fluke interception, Young was playing efficiently, particularly finding multiple tight ends.

He finished 28-of-39 for 276 and three touchdowns.

But they continued to struggle with penalties, specifically on Wilson and Thornton. They finished with 13 penalties for 119 yards.