Matthew Stafford looked like he was going to try to run for a 4-yard touchdown. The Rams quarterback thought better of it as he rolled right, seeing the 49ers defense blocking his path.

Then, it appeared he was going to throw it away and live to see another day.

Davis Allen, though, popped open at the back of the end zone. The 4-yard touchdown throw to Allen was the 400th of Stafford's career.

He joins Tom Brady (649), Drew Brees (571), Peyton Manning (539), Aaron Rodgers (517), Brett Favre (508), Philip Rivers (421), Dan Marino (420) and Ben Roethlisberger (418) in the elite club.

Stafford is 11-for-16 for 139 yards and two touchdowns, with his first scoring toss going to Puka Nacua for 22 yards.

The Rams lead the 49ers 21-0.