Barkley, who jumped to the Eagles in March after six seasons with the rival New York Giants, ran 24 times for 109 yards and two touchdowns and caught two passes for 23 yards and a touchdown in a landmark thriller.
The "Love Hurts" meeting saw Green Bay quarterback Jordan Love and Eagles counterpart Jalen Hurts stage a high-scoring spectacle in the historic Brazil contest, played in Sao Paulo's Neo Quimica Arena.
Hurts completed 20-of-34 passes for 278 yards with two touchdowns and two interceptions while Love completed half his 34 passes for 260 yards with two touchdown passes and an interception before a late-game ankle injury.
Hurts hurled a 67-yard touchdown pass to A.J. Brown on the Eagles' second play of the third quarter as Philadelphia grabbed a 24-19 edge. Brown evaded a defender and ran the last 40 yards across the field after making the catch.
Two third-down Eagles penalties helped sustain Green Bay's 70-yard scoring march in response, Love flipping a 2-yard touchdown pass to Christian Watson as the Packers reclaimed the lead 26-24.
Love was picked off by Eagles safety Reed Blankenship at the Packers 24-yard line and four plays later Barkley ran two yards up the middle for his third touchdown of the game, giving the Eagles a 31-26 edge with 4:26 left in the third.
Green Bay's Brayden Narveson kicked a 26-yard field goal with 7:52 remaining to pull within 31-29.
But when the Eagles got the ball, Hurts and Barkley guided a masterful march of 67 yards over 16 plays and more than seven minutes that ended on Jake Elliott's 21-yard field goal to give the Eagles their final margin and the Packers only 27 seconds to seek the winning points.
Love threw a 33-yard pass to Jayden Reed to reach Eagles territory in the dying seconds but suffered a left ankle injury on the next play and Malik Willis was sacked two plays later to end the game.
The first Friday game since 1970 in the NFL's opening week was the first of five matchups outside US venues, including three October games in London and a November contest in Munich, Germany.
Hurts woeful then solid
Green Bay safety Xavier McKinney, who spent four years with the New York Giants before joining the Packers in March, intercepted a Hurts pass to set up Narveson's 31-yard field goal.
On the next series, Hurts fumbled and Green Bay's Devonte Wyatt recovered at the Eagles 13-yard line to set up a 23-yard Narveson field goal for a 6-0 Packers lead after the first quarter.
Hurts responded by marching the Eagles 70 yards in 11 plays and capped the scoring drive with an 18-yard touchdown pass to Barkley, making the catch over a defender to give Philadelphia a 7-6 edge.
Green Bay answered on receiver Reed's 33-yard touchdown run around right end to close a five-play, 70-yard drive, but Josh Jacobs was stopped on a 2-point conversion run attempt, keeping the Packers' lead at 12-7.
Hurts threw for 50 yards and ran for seven on the next Eagles' drive to set up Barkley's 11-yard touchdown run, lifting Philadelphia back into the lead 5:34 before half-time.
Love responded only three plays after the ensuing kicking, throwing a 70-yard touchdown pass to Reed as the Packers reclaimed the lead.
Elliott kicked a 38-yard field goal to pull the Eagles within 19-17 at half-time.
