While the Eagles have scored the most points in the NFL in the final period, the Niners remain the only team in the league yet to score in the fourth.
Philadelphia's second-half fireworks have helped them become the first team in NFL history to win their first three games after trailing by 10 or more points in each tilt. San Francisco, meanwhile, has been outscored by a league-worst 49 points over the final two quarters.
Quarterback play has been a factor.
Nick Foles has been something of a hot-and-cold act for the Eagles, but his 978 passing yards leads the NFL en route to becoming the only player in the league with 300-plus passing yards in all three games. Foles is currently on pace for 5,216 pass yards, which would land him fourth all-time on the single-season passing list.
Something has to give Sunday, though, as the Niners defense has yet to allow a 300-yard passer in 2014.