Denver Broncos at San Francisco 49ers

Brock Purdy throws 2 TD passes to lead the undefeated 49ers past the Broncos 24-14

Brock Purdy threw two touchdown passes and Christian McCaffrey ran for a score as the 49ers scored touchdowns on three straight second-half possessions to beat the Denver Broncos 24-14 on Sunday to remain undefeated.

Both offenses struggled to generate offense on a hot day in the Bay Area, but the 49ers (4-0) took advantage of a fumbled punt return by Marvin Mims Jr. to set up a short touchdown drive in the third quarter that gave them the lead for good.

San Francisco had been held to three points on seven possessions before the takeaway that set the stage for three straight touchdowns as the Niners took advantage of injuries that knocked out both of Denver's starting cornerbacks, including two-time All Pro Patrick Surtain II.

“We wanted to break through whatever that was and just be ourselves,” Purdy said. “I'm glad we could get some momentum going in the second half. That's why it's a four-quarter game.”

Purdy capped the 28-yard drive with a 1-yard touchdown pass to Deebo Samuel that made it 10-3 late in the third quarter. He then engineered a 74-yard drive that McCaffrey finished with a 1-yard run to extend the lead to 17-6 midway through the fourth after the Broncos (2-2) had settled for a field goal on fourth-and-2.

Bo Nix, who has thrived in late-game comeback situations, tried to mount another for Denver with his 13-yard touchdown pass to Jaylen Waddle cutting the Niners' lead to 17-14 with a 2-point conversion with 4:05 to play.

But the 49ers sealed the win when Kittle took a screen pass behind the line of scrimmage and outraced former teammate Talanoa Hufanga for a 56-yard touchdown with 2:15 to go.

“Any time you see green grass, I think I ran the entire time with a smile on my face,” said Kittle, who'll turn 33 on Friday. “Always outrunning younger, old teammates is always a good time, especially when they’re (27).”

Purdy finished 19 of 30 for 218 yards and avoided taking a sack for a fourth straight game and had no turnovers.

Nix struggled to push the ball downfield most of the game with Denver's running game unable to loosen up the defense. He finished 25 of 42 for 214 yards and one touchdown.

“We just didn’t have enough offense to get a lead and then go beyond that,” coach Sean Payton said. “We just didn’t have enough answers to get past that and get a lead.”

The 49ers came in scoring touchdowns on nearly half of their possessions, but struggled to move the ball against Denver's stout defense. They punted on two of their first three possessions with Purdy getting stopped on a fourth-down sneak on the other.

San Francisco got on the board with a 24-yard field goal to tie it late in the first half, but had a chance to take the lead thwarted when a field goal was blocked on the final play of the first half to keep the game tied at 3.

“I think we had plays to be made," Nix said. “I think as a team there were plays out there for us that needed to be made.”

Injuries Broncos: Surtain (ankle), CB Riley Moss (ribs) and WR Pat Bryant (ankle) all left with injuries and didn't return. Payton had no immediate word on the extent of the injuries.

49ers: FB Kyle Juszczyk left with a sprained knee injury after being hit by Jahdae Barron and didn't return. ... S Marques Sigle (ankle) and CB Upton Stout (shoulder) also left. Shanahan had no immediate word on the extent of the injuries.

Up next Broncos: Visit the Los Angeles Chargers next Sunday.

49ers: Visit Seattle next Sunday.

See AP’s full NFL coverage here

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