CLEVELAND -- Cleveland Browns quarterback PJ Walker told everyone around him that the San Francisco 49ers would miss their potential game-winning field goal attempt.
Sure enough, Jake Moody's kick sailed wide right with six seconds left on the clock. And the Browns (3-2) held on for a stunning 19-17 victory, their first double-digit comeback win in more than five years.
"That's a good football team," Cleveland coach Kevin Stefanski said of the 49ers, who entered the weekend 5-0 and No. 1 in ESPN's Power Rankings. "The truth is, we're a good football team ... and we fought like crazy today."
The Browns named Walker their starter this week to replace Deshaun Watson, who missed his second straight game with an injury to his throwing shoulder.
With Watson out, the Browns entered the game as a 9.5-point underdog, making this their largest upset win since 2010, according to ESPN Stats & Information research.
A banged-up Browns offense was already without two All-Pro players in running back Nick Chubb, who suffered a season-ending knee injury in Week 2, and left guard Joel Bitonio, who underwent knee surgery last week.
Cleveland signed Walker to its practice squad after the Chicago Bears cut him during the preseason. But after spending the first month of the year running the scout-team offense behind Watson and rookie Dorian Thompson-Robinson from the practice squad, the Browns gave Walker his shot this week.
Walker threw a critical interception in the fourth quarter that allowed the 49ers to take a 17-13 lead. But he came right back to lead the Browns on back-to-back field goal drives to give them back the lead.
Walker finished with 192 passing yards.
"I've been in that situation before," said Walker, who made seven starts over the previous three seasons with the Carolina Panthers. "You're gonna make mistakes. But can you overcome them?"
The win by Cleveland ended San Francisco's 15-game regular-season winning streak, which tied a franchise record.
"We went in thinking it was going to be a grimy game like it was," 49ers coach Kyle Shanahan said. "We would have felt really good initially coming in if we'd made that [field goal attempt] on the last play. My message to them was regardless of whether we hit that or not, there's a lot of stuff from this game that we've got to improve on. I thought we made way too many mistakes on offense, losing a couple guys in the game, we had to switch a couple guys around, and we weren't quite ready for that, which starts with me with too many mistakes.
"This is our first time having to come in after a loss in a long time, and it's time to get back in, go to work and make sure we come back next week stronger."
It was Cleveland's first double-digit comeback under Stefanski (the Browns trailed San Francisco 10-0 in the first half). Their previous one came in 2018, when then-rookie quarterback Baker Mayfield came off the bench to spearhead a Thursday night victory over the New York Jets.
Stefanski admitted he was aware of how big of an underdog the Browns were. But he also said he "felt good" about the game, in large part due to a Cleveland defense that entered Sunday ranked No. 1 in efficiency.
"Their energy was off the charts," Stefanski said. "They were excited for this challenge."
San Francisco had scored 30 or more points in eight consecutive games. But the Browns held the 49ers to just 215 yards of offense and recorded the first interception of the season against quarterback Brock Purdy. Myles Garrett got a hand on the pass at the line of scrimmage and cornerback MJ Emerson picked it off.
The Browns' defense has now allowed just 1,002 yards combined this season. That's the third fewest through a team's first five games since the 1970 merger, according to ESPN Stats & Information.
"We found a way to win," Garrett said. "When the chips are down and the odds are against, you gotta make the most of what you got."
ESPN's Nick Wagoner contributed to this report.