He wasn't smiling because he was happy Jackson made him look silly on the deep pass, or because he was able to trip the three-time Pro Bowl receiver at the 4-yard line.
He wasn't smiling because quarterback Mike Glennon lost a fumble three plays later, even though he was happy the defense took him off the hook.
He was smiling because Jackson didn't catch another pass on him the rest of the game.
"You can't let one play worry you,'' Florence said. "You have to move on to the next play and make sure it doesn't happen again.''
A week ago, the Panthers didn't do that. Miami wide receiver Mike Wallace beat cornerback Captain Munnerlyn for completions of 53 and 57 yards. He had another where he was overthrown and he ended the game getting behind the secondary for what ultimately was an incompletion near the end zone.
Those plays were so scary that coach Ron Rivera opened the competition at both corners this past week, not naming his starters until Sunday.
Not even Munnerlyn, the senior member of the secondary, was guaranteed a spot outside the nickel position.
Florence was the benefactor, replacing rookie Melvin White at right corner in the base defense.
One play aside, Rivera was pleased.
"I thought our secondary did a nice job disguising,'' he said. "They did a nice job jamming and being physical when they had to. We did it again -- bite on the double move -- but it was a great effort by Drayton Florence to get him down.''
Still, he admitted, "There are some things that need to be cleaned up.''
The Panthers (9-3) can't afford such mistakes against New Orleans (9-2), which with quarterback Drew Brees and his stable full of talented receivers has the second-best passing attack in the NFL.
But Sunday's performance was a step in the right direction because the Panthers did a nice job of keeping plays in front of them as this defense requires.
Munnerlyn says the secondary passed whatever test Rivera and the coaching staff had for it. Florence agreed, saying competition makes everyone better.
Both like the way the defense is playing as a whole heading to New Orleans.
"The only way teams are going to beat us is if we beat ourselves,'' Florence said.
That almost happened at Miami, so Rivera adjusted. Other than the 60-yarder to Jackson, the adjustments worked.
That's why Florence was smiling.
"We responded like we've been responding all year,'' he said. "When teams get down in the red zone we come up with big plays, getting the turnover or holding them to three.
"It's big for our defense to keep playing like that. That's what's going to separate us once we get into the playoffs.''