Cam Newton's sideline celebration costs Panthers TD

The ol' "point of emphasis" got Cam Newton on Thursday night.

Late in the first quarter of the first preseason game, Carolina Panthers linebacker A.J. Klein picked off a bobbled catch attempt by Ravens receiver Darren Waller and sprinted 95 yards with a convoy of blockers for a touchdown.

The TD would not stand.

The score was wiped out by a penalty on Cam Newton. Officially it goes down as an "illegal substitution" because Newton ran on the field celebrating prematurely as Klein streaked for the score. Instead of a touchdown, the Panthers got the ball at the 26-yard-line.

"I just got too excited," Newton told reporters after the 22-19 loss, per ESPN. "I was hoping they would give a warning."

The touchdown was taken away from Klein, but QB2, Derek Anderson, made sure the Panthers got the points, tossing a back-shoulder touchdown to Devin Funchess several plays later.

The NFL made sideline penalties for players and coaches breaching the boundary during play a point of emphasis this season.

"We were told about them," Panthers coach Ron Rivera said. "We met with the referees about them, and we still did them, so I'm disappointed with that."

On the plus side, if you are going to get a silly penalty that wipes a touchdown, best get it in the preseason.

"It's a lesson learned," Rivera said. "If you're going to do it, do it now."

Newton doesn't plan to make the same mistake when the games count.

"You live and you learn," he said. "...It happened. We all learned something as a team. We're moving forward."