MIAMI GARDENS, Fla. – The 49ers’ last-ranked run defense had the answers on Sunday against Miami Dolphins running back Jay Ajayi.
But the 49ers were seemingly helpless to defend against quarterback Ryan Tannehill, who came through with one of the best games of his five-year career.
“I think our guys did a good job against a really good back,” 49ers coach Chip Kelly said. “If you can hold him to that (low yardage), you’d be in a good situation.
“We got to do a better job on the back end in terms of covering their receivers. We did take away the run game, but I think we got to do a better job in coverage stuff.”
Ajayi entered the game tied for sixth in the NFL in rushing with 802 yards, including a 5.6-yards-per-carry average. The 49ers put the clamps on him. He gained just 45 yards rushing on 18 attempts, as Miami was without three starting offensive linemen.
“We’ve been focusing on stopping the run, so we’re going to get in the box and stop the run,” 49ers safety Antoine Bethea said.
The 49ers entered the game with a league-worst average of surrendering 179.5 yards rushing per game. After holding the Dolphins to 95 yards on 26 carries, the average dropped to 171.8 yards per game.
“We don’t look at the rankings or anything like that,” Dolphins coach Adam Gase said. “We just knew we had a tough matchup. We had some new bodies as guys were trying to play together as far as our chemistry goes.”
Said Ajayi, “They did a good job. They got good players over there. It’s tough, but at the end of the day, we got the win.”
The Dolphins, who won for the sixth consecutive times, rode the arm of Tannehill to the victory. He completed 20 of 30 pass attempts for 285 yards with three touchdowns and no interceptions. His 130.6 passer rating tied for the second-best mark of his career.
Tannehill said the Dolphins were prepared in case the yards were going to be difficult on the ground.
“We knew it was a possibility, and figured that out early in the game that they were going to load the box and make it tough on us,” Tannehill said. “We tried to stick with it there throughout the whole game, tried to keep pounding away.”
Tannehill had two pass plays of more than 40 yards, including a 43-yard throw to Kenny Stills for a 43-yard touchdown that gave Miami a 24-14 lead in the third quarter.