PHILADELPHIA — As the Browns put the final touches on their preparations for the season opener, Hue Jackson said on Friday any pre-game speeches would come from the heart. But the first-year coach was confident his club wouldn't need any extra motivation against the Eagles.

"I don't think they need me up there with some fiery speech to get them to play," Jackson said. "I think our guys understand and know what the situation is."

He was right.

The Browns were plenty game in front of a lively crowd in Philadelphia, but a slow start and mistakes ultimately undid Cleveland in a 29-10 loss Sunday at Lincoln Financial Field

In a game of momentum swings, the Browns mounted a comeback behind big plays and a feisty defensive effort that thwarted the Eagles time and again on third down.

Browns quarterback Robert Griffin III, who made his first start since 2014, completed 12-of-26 passes for 190 yards, one interception and ran for 26 yards.

Five different Browns caught at least two passes, including rookie receiver Corey Coleman (two for 69 yards), Terrelle Pryor (three for 68) and running back Duke Johnson (three for 28). The

Isaiah Crowell, who said last week he was eager to shoulder the load of the Browns run game, rushed for a touchdown on 11 carries and proved to be an effective weapon in the pass game.

The Browns defense — a retooled unit filled with new faces — held the Eagles to 4-of-14 on third down conversions and applied plenty of pressure to rookie quarterback Carson Wentz. Carl Nassib, the rookie from Penn State, notched a sack and a pass deflection to continue what was an impressive preseason. So did Emmanuel Ogbah, the second-round pick from Oklahoma State, who batted down a pass in the backfield early in the game.

Even so, Sunday's display wasn't enough to overcome a tenacious Eagles defense and an untimely safety — an errant snap that  sailed past Griffin and into the end zone — in the third quarter that was something of a turning point on this afternoon.

Wentz, the second-overall pick in this past spring's NFL Draft, was impressive in his debut, completing 22-of-37 passes for 278 yards and a pair of touchdown passes, including a 35-yard lob to Nelson Agholor that gave the Eagles their largest lead late in the third quarter.

Trailing 10-0, the Browns sprung to to life in the second quarter with a seven-play, 75-yard drive capped by a two-yard touchdown run by Crowell. Cleveland kept that momentum flowing in the second half, opening their first series with a 58-yard pass to Coleman that set up a field goal to pull within three points of the Eagles lead.

The Browns offense, which finished with 248 total yards, struggled down the stretch, converting 2-of-10 attempts on third down.

Cleveland is set to host the Ravens next Sunday at FirstEnergy Stadium. ​