His first series ended with a three-and-out, but he quickly led the Browns on an impressive touchdown drive the next time he got the ball.
5 - Tyrod Taylor was 5-for-5 for 99 yards and the aforementioned touchdown to Njoku before exiting.
Besides not figuring out how to cover Njoku, the Giants allowed Mayfield to a convert on third-and-18 with a 21-yard completion to wide receiver C.J. Board. The drive included conversions on third and long and fourth and two.
The second of those scampers - a 5-yard, red-zone dash on fourth-and-2 - set up Mayfield's 10-yard touchdown toss to David Njoku.
141 - Number of penalty yards the Browns had on 13 penalties, including two for taunting.
Davis Webb struggled tremendously with accuracy throughout the night, completing just 41 percent of his passes and failing to connect on anything down the field.
"I thought he did some good things out there", Cleveland coach Hue Jackson said. Rookie Antonio Callaway and third-year receiver Rashard Higgins are expected to get the first opportunities to fill that spot now. Barkley ripped off a 39-yard run on his first National Football League touch that began with a nasty Barry Sanders-esque jump cut in the backfield.
"There were stretches that were positive", Giants head coach Pat Shurmur said.
The pass defense wasn't so good.
It marked the second touchdown of the game for Mayfield and pushed his line up to 212 passing yards and two passing touchdowns on 20 attempts.
But Cleveland couldn't have been more pleased with Mayfield, who intermixed his big-play penchant with mostly sound decision making, all while bringing the energy and leadership skills that have defined his rise from former walk-on to Heisman to the man who's tasked with restoring the NFL's most hopeless franchise.
GIANTS WOES: This looked a lot like the Giants of past year. Shepard was a senior. "I don't see anything that's going to hold that guy back".