"Just an outstanding performance by all three phases," Sanchez said.
The Eagles (7-2) stayed on top in the NFC East. They're trying to repeat as division champions without Foles, who broke his collarbone in a win at Houston last week.
Conor Barwin had 3½ sacks and Brandon Graham had 1 ½. Newton had never been sacked more than seven times in his career.
"We wanted to keep Cam in the pocket and if we didn't, we didn't want him to go north, we just wanted him to go east and west and we did that," Barwin said. "Nobody gave him a hole to rush through. Everyone stayed disciplined and he didn't really know where to go when he tried to escape."
The game was in Philadelphia's control when Newton threw a pair of fourth-quarter TDs to Kelvin Benjamin.
Sanchez, the former franchise quarterback for the New York Jets, signed a one-year deal to back up Foles after missing last season following shoulder surgery. Though he led the Jets to the AFC championship game his first two seasons, he didn't live up to enormous expectations in New York after being picked fifth in the 2009 draft.
But one day before his 28th birthday Sanchez had one of the best games of his career in his first start in Chip Kelly's up-tempo, quarterback-friendly offense.
"After playing for a while, you learn a lot," he said. "I've made plenty of mistakes and hurt the team. The most important thing was taking care of the football, communicating well and executing. If we do that, generally we'll be successful. There are still plenty of things to clean up though. By no means was this perfect."
"Our defense really came to play," Kelly said. "We created a lot of pressure early and those two turnovers on the first three plays really set the tempo for the day."
"I have to protect the football better," Newton said. "I can't throw the football up for grabs and have to understand the difference between giving my guys a chance or opportunity and risking the football. In the pocket, man I got to do better."
LeSean McCoy ran in from the 1 to make it 38-7. Matthews caught an 18-yard TD pass in the fourth quarter.
Benjamin had TD catches of 21 and 40 yards.
NOTES: LG Evan Mathis was back after missing seven games for the Eagles. Matt Tobin moved from LG to RG to replace Todd Herremans. ... Newton had his first multi-interception regular-season game since Dec. 1, 2013, vs. Tampa. He threw two in a playoff loss to San Francisco ... The Panthers have allowed 37 or more points in five of their 10 games this season. ... Eagles TE Brent Celek had 116 yards receiving. ... Olsen had 119 yards receiving.
Copyright 2014 by The Associated Press