"We have to accept the task at hand and make the most of it because playoff football is a different speed than the regular season," Newton said. "I learned that firsthand today.
"You have to seize the moment when a moment allows. We had too many opportunities that we let slip through our hands. That was just the story of the day."
It took Newton, the former Heisman Trophy winner who led Auburn to a national championship in 2010, three seasons to reach the playoffs. He led a Panthers team that started 1-3 to eight straight wins to turn around their season and win the franchise's fourth division title, the No. 2 playoff seed and a first-round bye.
Playing in front of a sellout home crowd in Carolina's first playoff appearance since 2008, Newton shook off a first-series interception and had the Panthers offense moving early. But Carolina struggled to finish first-half drives against a playoff-tested defense, then couldn't get much going through the second half as Colin Kaepernick got the 49ers back to the NFC championship game for the third straight season.
Newton wouldn't say it was his toughest loss.
"A loss is a loss," he said. "But [with] the preparation going into it, I felt as if I was ready more than any other game. Being that we took a loss, it's kind of hurtful."
Newton finished 16-for-25 for 267 yards passing with a perfectly thrown 31-yard touchdown throw to Steve Smith in the second quarter. His yardage got a late boost with a 59-yard catch and run by Ted Ginn Jr. in the final seconds with San Francisco up two scores.
Newton also ran for a team-best 54 yards on 10 carries, but the mistakes added up both for him and the Carolina offense. He threw two interceptions and twice came up short of the end zone on keepers from the 1.
He also was sacked five times, including on back-to-back plays to kill a promising third-quarter drive.
"I think Cam had his moments, did some really good things," Panthers coach Ron Rivera said. "Again, we have to protect him and give him opportunities. "