NASHVILLE, Tenn. Theories for Colin Kaepernick's meager rushing opportunities this season have ranged from the coaches' lack of faith in his backups to a mysterious foot injury to NFL defenses being better prepared for a new generation of running quarterbacks.
Sunday, however, nothing kept Kaepernick from gaining yards on the ground, including the Titans' defense. The 49ers quarterback ran 11 times, scored his first rushing touchdown of the season and propelled his team to a big halftime lead they would not relinquish in a 31-17 win.
The 49ers won their fourth straight game and also scored more than 30 points in four consecutive games for the first time since 1998.
Against the Titans, the 49ers used the formula that helped them snap out of a two-game skid last month a potent running game, a few timely passes and a defense that caused a turnover.
In this game, special teams also played a part when speedy gunner Darryl Morris caused Tennessee returner Darius Reynaud to muff a punt, and Kassim Osgood pounced on the loose ball in the end zone. The touchdown occurred at a point in the fourth quarter when the Titans, woebegone for most of the game, were threatening to crawl back into the contest.
"They were just playing with fire," Jim Harbaugh said of the special teams. " And the dream play by Darryl Morris and Kassim Osgood is one you lay awake at night and dream about. It looked like an arrow going through snow."
But the biggest difference maker was Kaepernick joining Frank Gore in the 49ers' ground attack. Gore finished with a game-high 70 rushing yards.
Kaepernick finished just behind him with 68 yards, including a 20-yard read-option touchdown run in the second quarter. It was the first time in 2013 he looked like his 2012 self.
Kaepernick faked an inside handoff to Gore, who took out the last defender in Kaepernick's path 15 yards downfield. Gore said that scenario happens sometimes in practice.
"If you don't get (the ball) and you get outside, go get the safety," he said of his instructions on the play. "And that's what happened."
Last season, when Kaepernick set a single-game rushing record for a quarterback against Green Bay, the 49ers had a starter-quality backup in Alex Smith. The team has seemed far more hesitant to let Kaepernick loose this season, and he had rushed eight times total in the last three games.
Both Harbaugh and Kaepernick, however, said read-option runs are a part of every game plan. It's just that the Titans' defense gave the 49ers opportunities.
"Sometimes you bring it out and you put it away. Then you take it back out," Harbaugh said. "It's a great tool to have. It's a club in our bag."
Kaepernick certainly wasn't tentative. He absorbed several big hits including one that drew an unnecessary roughness penalty that wiped away one of his few mistakes, an interception on a second-quarter pass intended for Vernon Davis.
The quarterback also found himself on his belly in the middle of a sideline scrum as he tried to corral what he thought was a fumbled football. The officials instead ruled it was an incomplete pass.
Kaepernick has been on the team's injury report at various points this season, including the last two weeks, because of a foot injury. No one on the team has divulged the exact ailment, but Kaepernick on Wednesday joked that he had a hangnail on his pinky toe. In fact, he said he had hangnails on both pinky toes.
Did they bother him Sunday?
"No," he said. "Hangnails are healed up."
Video highlights from 49ers' victory over Tennessee:
Read Matthew Barrows' blogs at www. sacbee.com/sf49ers and listen for his reports Tuesdays on ESPN Radio 1320.